Implement the deposit side of Voting Pools

This contains the APIs to create and retrieve Voting Pools and Series (with public/private keys) from a walletdb namespace, plus the generation of deposit addresses (using m-of-n multi-sig P2SH scripts according to the series configuration).
2014-06-13 12:14:44 -05:00 · 2014-06-13 12:14:44 -05:00 · 24dcd206d2
commit 24dcd206d2
parent 454d290b68
17 changed files with 2913 additions and 34 deletions
--- a/snacl/snacl.go
+++ b/snacl/snacl.go
@ -31,6 +31,8 @@ func zero(b []byte) {
 }

 const (
+	// Expose secretbox's Overhead const here for convenience.
+	Overhead  = secretbox.Overhead
 	KeySize   = 32
 	NonceSize = 24
 	DefaultN  = 16384 // 2^14
--- a/votingpool/README.md
+++ b/votingpool/README.md
@ -0,0 +1,40 @@
+votingpool
+========
+
+[![Build Status](https://travis-ci.org/conformal/btcwallet.png?branch=master)]
+(https://travis-ci.org/conformal/btcwallet)
+
+Package votingpool provides voting pool functionality for btcwallet as
+described here:
+[Voting Pools](http://opentransactions.org/wiki/index.php?title=Category:Voting_Pools).
+
+A suite of tests is provided to ensure proper functionality.  See
+`test_coverage.txt` for the gocov coverage report.  Alternatively, if you are
+running a POSIX OS, you can run the `cov_report.sh` script for a real-time
+report.  Package votingpool is licensed under the liberal ISC license.
+
+Note that this is still a work in progress.
+
+## Feature Overview
+
+- Create/Load pools
+- Create series
+- Replace series
+- Create deposit addresses
+- Comprehensive test coverage
+
+## Documentation
+
+[![GoDoc](https://godoc.org/github.com/conformal/btcwallet/votingpool?status.png)]
+(http://godoc.org/github.com/conformal/btcwallet/votingpool)
+
+Full `go doc` style documentation for the project can be viewed online without
+installing this package by using the GoDoc site here:
+http://godoc.org/github.com/conformal/btcwallet/votingpool
+
+You can also view the documentation locally once the package is installed with
+the `godoc` tool by running `godoc -http=":6060"` and pointing your browser to
+http://localhost:6060/pkg/github.com/conformal/btcwallet/votingpool
+
+Package votingpool is licensed under the [copyfree](http://copyfree.org) ISC
+License.
--- a/votingpool/cov_report.sh
+++ b/votingpool/cov_report.sh
@ -0,0 +1,17 @@
+#!/bin/sh
+
+# This script uses gocov to generate a test coverage report.
+# The gocov tool my be obtained with the following command:
+#   go get github.com/axw/gocov/gocov
+#
+# It will be installed to $GOPATH/bin, so ensure that location is in your $PATH.
+
+# Check for gocov.
+type gocov >/dev/null 2>&1
+if [ $? -ne 0 ]; then
+	echo >&2 "This script requires the gocov tool."
+	echo >&2 "You may obtain it with the following command:"
+	echo >&2 "go get github.com/axw/gocov/gocov"
+	exit 1
+fi
+gocov test | gocov report
--- a/votingpool/db.go
+++ b/votingpool/db.go
@ -0,0 +1,283 @@
+/*
+ * Copyright (c) 2014 Conformal Systems LLC <info@conformal.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package votingpool
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+
+	"github.com/conformal/btcwallet/snacl"
+	"github.com/conformal/btcwallet/waddrmgr"
+	"github.com/conformal/btcwallet/walletdb"
+)
+
+// These constants define the serialized length for a given encrypted extended
+//  public or private key.
+const (
+	// We can calculate the encrypted extended key length this way:
+	// snacl.Overhead == overhead for encrypting (16)
+	// actual base58 extended key length = (111)
+	// snacl.NonceSize == nonce size used for encryption (24)
+	seriesKeyLength = snacl.Overhead + 111 + snacl.NonceSize
+	// 4 bytes version + 1 byte active + 4 bytes nKeys + 4 bytes reqSigs
+	seriesMinSerial = 4 + 1 + 4 + 4
+	// 15 is the max number of keys in a voting pool, 1 each for
+	// pubkey and privkey
+	seriesMaxSerial = seriesMinSerial + 15*seriesKeyLength*2
+	// version of serialized Series that we support
+	seriesMaxVersion = 1
+)
+
+var (
+	// string representing a non-existent private key
+	seriesNullPrivKey = [seriesKeyLength]byte{}
+)
+
+type dbSeriesRow struct {
+	version           uint32
+	active            bool
+	reqSigs           uint32
+	pubKeysEncrypted  [][]byte
+	privKeysEncrypted [][]byte
+}
+
+// putPool stores a voting pool in the database, creating a bucket named
+// after the voting pool id.
+func putPool(tx walletdb.Tx, votingPoolID []byte) error {
+	_, err := tx.RootBucket().CreateBucket(votingPoolID)
+	if err != nil {
+		str := fmt.Sprintf("cannot create voting pool %v", votingPoolID)
+		return managerError(waddrmgr.ErrDatabase, str, err)
+	}
+	return nil
+}
+
+// loadAllSeries returns a map of all the series stored inside a voting pool
+// bucket, keyed by id.
+func loadAllSeries(tx walletdb.Tx, votingPoolID []byte) (map[uint32]*dbSeriesRow, error) {
+	bucket := tx.RootBucket().Bucket(votingPoolID)
+	allSeries := make(map[uint32]*dbSeriesRow)
+	err := bucket.ForEach(
+		func(k, v []byte) error {
+			seriesID := bytesToUint32(k)
+			series, err := deserializeSeriesRow(v)
+			if err != nil {
+				str := fmt.Sprintf("cannot deserialize series %v", v)
+				return managerError(waddrmgr.ErrSeriesStorage, str, err)
+			}
+			allSeries[seriesID] = series
+			return nil
+		})
+	if err != nil {
+		return nil, err
+	}
+	return allSeries, nil
+}
+
+// existsPool checks the existence of a bucket named after the given
+// voting pool id.
+func existsPool(tx walletdb.Tx, votingPoolID []byte) bool {
+	bucket := tx.RootBucket().Bucket(votingPoolID)
+	return bucket != nil
+}
+
+// putSeries stores the given series inside a voting pool bucket named after
+// votingPoolID. The voting pool bucket does not need to be created beforehand.
+func putSeries(tx walletdb.Tx, votingPoolID []byte, version, ID uint32, active bool, reqSigs uint32, pubKeysEncrypted, privKeysEncrypted [][]byte) error {
+	row := &dbSeriesRow{
+		version:           version,
+		active:            active,
+		reqSigs:           reqSigs,
+		pubKeysEncrypted:  pubKeysEncrypted,
+		privKeysEncrypted: privKeysEncrypted,
+	}
+	return putSeriesRow(tx, votingPoolID, ID, row)
+}
+
+// putSeriesRow stores the given series row inside a voting pool bucket named
+// after votingPoolID. The voting pool bucket does not need to be created
+// beforehand.
+func putSeriesRow(tx walletdb.Tx, votingPoolID []byte, ID uint32, row *dbSeriesRow) error {
+	bucket, err := tx.RootBucket().CreateBucketIfNotExists(votingPoolID)
+	if err != nil {
+		str := fmt.Sprintf("cannot create bucket %v", votingPoolID)
+		return managerError(waddrmgr.ErrDatabase, str, err)
+	}
+	serialized, err := serializeSeriesRow(row)
+	if err != nil {
+		str := fmt.Sprintf("cannot serialize series %v", row)
+		return managerError(waddrmgr.ErrSeriesStorage, str, err)
+	}
+	err = bucket.Put(uint32ToBytes(ID), serialized)
+	if err != nil {
+		str := fmt.Sprintf("cannot put series %v into bucket %v", serialized, votingPoolID)
+		return managerError(waddrmgr.ErrSeriesStorage, str, err)
+	}
+	return nil
+}
+
+// deserializeSeriesRow deserializes a series storage into a dbSeriesRow struct.
+func deserializeSeriesRow(serializedSeries []byte) (*dbSeriesRow, error) {
+	// The serialized series format is:
+	// <version><active><reqSigs><nKeys><pubKey1><privKey1>...<pubkeyN><privKeyN>
+	//
+	// 4 bytes version + 1 byte active + 4 bytes reqSigs + 4 bytes nKeys
+	// + seriesKeyLength * 2 * nKeys (1 for priv, 1 for pub)
+
+	// Given the above, the length of the serialized series should be
+	// at minimum the length of the constants.
+	if len(serializedSeries) < seriesMinSerial {
+		str := fmt.Sprintf("serialized series is too short: %v",
+			serializedSeries)
+		return nil, managerError(waddrmgr.ErrSeriesStorage, str, nil)
+	}
+
+	// Maximum number of public keys is 15 and the same for public keys
+	// this gives us an upper bound.
+	if len(serializedSeries) > seriesMaxSerial {
+		str := fmt.Sprintf("serialized series is too long: %v",
+			serializedSeries)
+		return nil, managerError(waddrmgr.ErrSeriesStorage, str, nil)
+	}
+
+	// Keeps track of the position of the next set of bytes to deserialize.
+	current := 0
+	row := dbSeriesRow{}
+
+	row.version = bytesToUint32(serializedSeries[current : current+4])
+	if row.version > seriesMaxVersion {
+		str := fmt.Sprintf("deserialization supports up to version %v not %v",
+			seriesMaxVersion, row.version)
+		return nil, managerError(waddrmgr.ErrSeriesVersion, str, nil)
+	}
+	current += 4
+
+	row.active = serializedSeries[current] == 0x01
+	current++
+
+	row.reqSigs = bytesToUint32(serializedSeries[current : current+4])
+	current += 4
+
+	nKeys := bytesToUint32(serializedSeries[current : current+4])
+	current += 4
+
+	// Check to see if we have the right number of bytes to consume.
+	if len(serializedSeries) < current+int(nKeys)*seriesKeyLength*2 {
+		str := fmt.Sprintf("serialized series has not enough data: %v",
+			serializedSeries)
+		return nil, managerError(waddrmgr.ErrSeriesStorage, str, nil)
+	} else if len(serializedSeries) > current+int(nKeys)*seriesKeyLength*2 {
+		str := fmt.Sprintf("serialized series has too much data: %v",
+			serializedSeries)
+		return nil, managerError(waddrmgr.ErrSeriesStorage, str, nil)
+	}
+
+	// Deserialize the pubkey/privkey pairs.
+	row.pubKeysEncrypted = make([][]byte, nKeys)
+	row.privKeysEncrypted = make([][]byte, nKeys)
+	for i := 0; i < int(nKeys); i++ {
+		pubKeyStart := current + seriesKeyLength*i*2
+		pubKeyEnd := current + seriesKeyLength*i*2 + seriesKeyLength
+		privKeyEnd := current + seriesKeyLength*(i+1)*2
+		row.pubKeysEncrypted[i] = serializedSeries[pubKeyStart:pubKeyEnd]
+		privKeyEncrypted := serializedSeries[pubKeyEnd:privKeyEnd]
+		if bytes.Equal(privKeyEncrypted, seriesNullPrivKey[:]) {
+			row.privKeysEncrypted[i] = nil
+		} else {
+			row.privKeysEncrypted[i] = privKeyEncrypted
+		}
+	}
+
+	return &row, nil
+}
+
+// serializeSeriesRow serializes a dbSeriesRow struct into storage format.
+func serializeSeriesRow(row *dbSeriesRow) ([]byte, error) {
+	// The serialized series format is:
+	// <version><active><reqSigs><nKeys><pubKey1><privKey1>...<pubkeyN><privKeyN>
+	//
+	// 4 bytes version + 1 byte active + 4 bytes reqSigs + 4 bytes nKeys
+	// + seriesKeyLength * 2 * nKeys (1 for priv, 1 for pub)
+	serializedLen := 4 + 1 + 4 + 4 + (seriesKeyLength * 2 * len(row.pubKeysEncrypted))
+
+	if len(row.privKeysEncrypted) != 0 &&
+		len(row.pubKeysEncrypted) != len(row.privKeysEncrypted) {
+		str := fmt.Sprintf("different # of pub (%v) and priv (%v) keys",
+			len(row.pubKeysEncrypted), len(row.privKeysEncrypted))
+		return nil, managerError(waddrmgr.ErrSeriesStorage, str, nil)
+	}
+
+	if row.version > seriesMaxVersion {
+		str := fmt.Sprintf("serialization supports up to version %v, not %v",
+			seriesMaxVersion, row.version)
+		return nil, managerError(waddrmgr.ErrSeriesVersion, str, nil)
+	}
+
+	serialized := make([]byte, 0, serializedLen)
+	serialized = append(serialized, uint32ToBytes(row.version)...)
+	if row.active {
+		serialized = append(serialized, 0x01)
+	} else {
+		serialized = append(serialized, 0x00)
+	}
+	serialized = append(serialized, uint32ToBytes(row.reqSigs)...)
+	nKeys := uint32(len(row.pubKeysEncrypted))
+	serialized = append(serialized, uint32ToBytes(nKeys)...)
+
+	var privKeyEncrypted []byte
+	for i, pubKeyEncrypted := range row.pubKeysEncrypted {
+		// check that the encrypted length is correct
+		if len(pubKeyEncrypted) != seriesKeyLength {
+			str := fmt.Sprintf("wrong length of Encrypted Public Key: %v",
+				pubKeyEncrypted)
+			return nil, managerError(waddrmgr.ErrSeriesStorage, str, nil)
+		}
+		serialized = append(serialized, pubKeyEncrypted...)
+
+		if len(row.privKeysEncrypted) == 0 {
+			privKeyEncrypted = seriesNullPrivKey[:]
+		} else {
+			privKeyEncrypted = row.privKeysEncrypted[i]
+		}
+
+		if privKeyEncrypted == nil {
+			serialized = append(serialized, seriesNullPrivKey[:]...)
+		} else if len(privKeyEncrypted) != seriesKeyLength {
+			str := fmt.Sprintf("wrong length of Encrypted Private Key: %v",
+				len(privKeyEncrypted))
+			return nil, managerError(waddrmgr.ErrSeriesStorage, str, nil)
+		} else {
+			serialized = append(serialized, privKeyEncrypted...)
+		}
+	}
+	return serialized, nil
+}
+
+// uint32ToBytes converts a 32 bit unsigned integer into a 4-byte slice in
+// little-endian order: 1 -> [1 0 0 0].
+func uint32ToBytes(number uint32) []byte {
+	buf := make([]byte, 4)
+	binary.LittleEndian.PutUint32(buf, number)
+	return buf
+}
+
+// bytesToUint32 converts a 4-byte slice in little-endian order into a 32 bit
+// unsigned integer: [1 0 0 0] -> 1.
+func bytesToUint32(encoded []byte) uint32 {
+	return binary.LittleEndian.Uint32(encoded)
+}
--- a/votingpool/doc.go
+++ b/votingpool/doc.go
@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2014 Conformal Systems LLC <info@conformal.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+Package votingpool provides voting pool functionality for btcwallet.
+
+Overview
+
+The purpose of the voting pool package is to make it possible to store
+bitcoins using m-of-n multisig transactions. Each member of the pool
+holds one of the n private keys needed to create a transaction and can
+only create transactions that can spend the bitcoins if m - 1 other
+members of the pool agree to it.
+
+This package depends on the waddrmgr package, and in particular
+instances of the waddrgmgr.Manager structure.
+
+Creating a voting pool
+
+A voting pool is created via the Create function. This function
+accepts a database namespace which will be used to store all
+information about the pool as well as a poolID.
+
+Loading an existing pool
+
+An existing voting pool is loaded via the Load function, which accepts
+the database name used when creating the pool as well as the poolID.
+
+Creating a series
+
+A series can be created via the CreateSeries method, which accepts a
+version number, a series identifier, a number of required signatures
+(m in m-of-n multisig, and a set of public keys.
+
+Deposit Addresses
+
+A deposit address can be created via the DepositScriptAddress
+method, which based on a seriesID a branch number and an index
+creates a pay-to-script-hash address, where the script is a multisig
+script. The public keys used as inputs for generating the address are
+generated from the public keys passed to CreateSeries. In [1] the
+generated public keys correspend to the lowest level or the
+'address_index' in the hierarchy.
+
+Replacing a series
+
+A series can be replaced via the ReplaceSeries method. It accepts
+the same parameters as the CreateSeries method.
+
+
+Documentation
+
+[1] https://github.com/justusranvier/bips/blob/master/bip-draft-Hierarchy%20for%20Non-Colored%20Voting%20Pool%20Deterministic%20Multisig%20Wallets.mediawiki
+
+
+*/
+package votingpool
--- a/votingpool/example_test.go
+++ b/votingpool/example_test.go
@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2014 Conformal Systems LLC <info@conformal.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package votingpool_test
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/conformal/btcnet"
+	"github.com/conformal/btcwallet/votingpool"
+	"github.com/conformal/btcwallet/waddrmgr"
+	"github.com/conformal/btcwallet/walletdb"
+	_ "github.com/conformal/btcwallet/walletdb/bdb"
+)
+
+func Example_basic() {
+	// This example demonstrates how to create a voting pool, create a
+	// series, get a deposit address from a series and lastly how to
+	// replace a series.
+
+	// Create a new wallet DB.
+	dir, err := ioutil.TempDir("", "pool_test")
+	if err != nil {
+		fmt.Printf("Failed to create db dir: %v\n", err)
+		return
+	}
+	db, err := walletdb.Create("bdb", filepath.Join(dir, "wallet.db"))
+	if err != nil {
+		fmt.Printf("Failed to create wallet DB: %v\n", err)
+		return
+	}
+	defer os.RemoveAll(dir)
+	defer db.Close()
+
+	// Create a new walletdb namespace for the address manager.
+	mgrNamespace, err := db.Namespace([]byte("waddrmgr"))
+	if err != nil {
+		fmt.Printf("Failed to create addr manager DB namespace: %v\n", err)
+		return
+	}
+
+	// Create the address manager
+	mgr, err := waddrmgr.Create(mgrNamespace, seed, pubPassphrase, privPassphrase,
+		&btcnet.MainNetParams, nil)
+	if err != nil {
+		fmt.Printf("Failed to create addr manager: %v\n", err)
+		return
+	}
+	defer mgr.Close()
+
+	// Create a walletdb for votingpools.
+	vpNamespace, err := db.Namespace([]byte("votingpool"))
+	if err != nil {
+		fmt.Printf("Failed to create VotingPool DB namespace: %v\n", err)
+		return
+	}
+
+	// Create the voting pool.
+	pool, err := votingpool.Create(vpNamespace, mgr, []byte{0x00})
+	if err != nil {
+		fmt.Printf("Voting Pool creation failed: %v\n", err)
+		return
+	}
+
+	// Create a 2-of-3 series.
+	apiVersion := uint32(1)
+	seriesID := uint32(1)
+	requiredSignatures := uint32(2)
+	pubKeys := []string{
+		"xpub661MyMwAqRbcFDDrR5jY7LqsRioFDwg3cLjc7tML3RRcfYyhXqqgCH5SqMSQdpQ1Xh8EtVwcfm8psD8zXKPcRaCVSY4GCqbb3aMEs27GitE",
+		"xpub661MyMwAqRbcGsxyD8hTmJFtpmwoZhy4NBBVxzvFU8tDXD2ME49A6JjQCYgbpSUpHGP1q4S2S1Pxv2EqTjwfERS5pc9Q2yeLkPFzSgRpjs9",
+		"xpub661MyMwAqRbcEbc4uYVXvQQpH9L3YuZLZ1gxCmj59yAhNy33vXxbXadmRpx5YZEupNSqWRrR7PqU6duS2FiVCGEiugBEa5zuEAjsyLJjKCh",
+	}
+	err = pool.CreateSeries(apiVersion, seriesID, requiredSignatures, pubKeys)
+	if err != nil {
+		fmt.Printf("Cannot create series: %v\n", err)
+		return
+	}
+
+	// Create a deposit address.
+	branch := uint32(0) // The change branch
+	index := uint32(1)
+	addr, err := pool.DepositScriptAddress(seriesID, branch, index)
+	if err != nil {
+		fmt.Printf("DepositScriptAddress failed for series: %d, branch: %d, index: %d\n",
+			seriesID, branch, index)
+		return
+	}
+	fmt.Println("Generated deposit address:", addr.EncodeAddress())
+
+	// Replace the existing series with a 3-of-5 series.
+	pubKeys = []string{
+		"xpub661MyMwAqRbcFQfXKHwz8ZbTtePwAKu8pmGYyVrWEM96DYUTWDYipMnHrFcemZHn13jcRMfsNU3UWQUudiaE7mhkWCHGFRMavF167DQM4Va",
+		"xpub661MyMwAqRbcGnTEXx3ehjx8EiqQGnL4uhwZw3ZxvZAa2E6E4YVAp63UoVtvm2vMDDF8BdPpcarcf7PWcEKvzHhxzAYw1zG23C2egeh82AR",
+		"xpub661MyMwAqRbcG83KwFyr1RVrNUmqVwYxV6nzxbqoRTNc8fRnWxq1yQiTBifTHhevcEM9ucZ1TqFS7Kv17Gd81cesv6RDrrvYS9SLPjPXhV5",
+		"xpub661MyMwAqRbcFGJbLPhMjtpC1XntFpg6jjQWjr6yXN8b9wfS1RiU5EhJt5L7qoFuidYawc3XJoLjT2PcjVpXryS3hn1WmSPCyvQDNuKsfgM",
+		"xpub661MyMwAqRbcGJDX4GYocn7qCzvMJwNisxpzkYZAakcvXtWV6CanXuz9xdfe5kTptFMJ4hDt2iTiT11zyN14u8R5zLvoZ1gnEVqNLxp1r3v",
+		"xpub661MyMwAqRbcG13FtwvZVaA15pTerP4JdAGvytPykqDr2fKXePqw3wLhCALPAixsE176jFkc2ac9K3tnF4KwaTRKUqFF5apWD6XL9LHCu7E",
+	}
+	requiredSignatures = 3
+	err = pool.ReplaceSeries(apiVersion, seriesID, requiredSignatures, pubKeys)
+	if err != nil {
+		fmt.Printf("Cannot replace series: %v\n", err)
+		return
+	}
+
+	// Output:
+	// Generated deposit address: 3QTzpc9d3tTbNLJLB7xwt87nWM38boAhAw
+}
--- a/votingpool/internal_test.go
+++ b/votingpool/internal_test.go
@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2014 Conformal Systems LLC <info@conformal.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package votingpool
+
+import (
+	"github.com/conformal/btcutil/hdkeychain"
+	"github.com/conformal/btcwallet/waddrmgr"
+	"github.com/conformal/btcwallet/walletdb"
+)
+
+// TstPutSeries transparently wraps the voting pool putSeries method.
+func (vp *Pool) TstPutSeries(version, seriesID, reqSigs uint32, inRawPubKeys []string) error {
+	return vp.putSeries(version, seriesID, reqSigs, inRawPubKeys)
+}
+
+var TstBranchOrder = branchOrder
+
+// TstExistsSeries checks whether a series is stored in the database.
+func (vp *Pool) TstExistsSeries(seriesID uint32) (bool, error) {
+	return vp.existsSeries(seriesID)
+}
+
+// TstNamespace exposes the Pool's namespace as it's needed in some tests.
+func (vp *Pool) TstNamespace() walletdb.Namespace {
+	return vp.namespace
+}
+
+// TstGetRawPublicKeys gets a series public keys in string format.
+func (s *SeriesData) TstGetRawPublicKeys() []string {
+	rawKeys := make([]string, len(s.publicKeys))
+	for i, key := range s.publicKeys {
+		rawKeys[i] = key.String()
+	}
+	return rawKeys
+}
+
+// TstGetRawPrivateKeys gets a series private keys in string format.
+func (s *SeriesData) TstGetRawPrivateKeys() []string {
+	rawKeys := make([]string, len(s.privateKeys))
+	for i, key := range s.privateKeys {
+		if key != nil {
+			rawKeys[i] = key.String()
+		}
+	}
+	return rawKeys
+}
+
+// TstGetReqSigs expose the series reqSigs attribute.
+func (s *SeriesData) TstGetReqSigs() uint32 {
+	return s.reqSigs
+}
+
+// TstEmptySeriesLookup empties the voting pool seriesLookup attribute.
+func (vp *Pool) TstEmptySeriesLookup() {
+	vp.seriesLookup = make(map[uint32]*SeriesData)
+}
+
+// TstDecryptExtendedKey expose the decryptExtendedKey method.
+func (vp *Pool) TstDecryptExtendedKey(keyType waddrmgr.CryptoKeyType, encrypted []byte) (*hdkeychain.ExtendedKey, error) {
+	return vp.decryptExtendedKey(keyType, encrypted)
+}
+
+// SeriesRow mimics dbSeriesRow defined in db.go .
+type SeriesRow struct {
+	Version           uint32
+	Active            bool
+	ReqSigs           uint32
+	PubKeysEncrypted  [][]byte
+	PrivKeysEncrypted [][]byte
+}
+
+// SerializeSeries wraps serializeSeriesRow by passing it a freshly-built
+// dbSeriesRow.
+func SerializeSeries(version uint32, active bool, reqSigs uint32, pubKeys, privKeys [][]byte) ([]byte, error) {
+	row := &dbSeriesRow{
+		version:           version,
+		active:            active,
+		reqSigs:           reqSigs,
+		pubKeysEncrypted:  pubKeys,
+		privKeysEncrypted: privKeys,
+	}
+	return serializeSeriesRow(row)
+}
+
+// DeserializeSeries wraps deserializeSeriesRow and returns a freshly-built
+// SeriesRow.
+func DeserializeSeries(serializedSeries []byte) (*SeriesRow, error) {
+	row, err := deserializeSeriesRow(serializedSeries)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &SeriesRow{
+		Version:           row.version,
+		Active:            row.active,
+		ReqSigs:           row.reqSigs,
+		PubKeysEncrypted:  row.pubKeysEncrypted,
+		PrivKeysEncrypted: row.privKeysEncrypted,
+	}, nil
+}
+
+var TstValidateAndDecryptKeys = validateAndDecryptKeys
--- a/votingpool/pool.go
+++ b/votingpool/pool.go
@ -0,0 +1,620 @@
+/*
+ * Copyright (c) 2014 Conformal Systems LLC <info@conformal.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package votingpool
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/conformal/btcscript"
+	"github.com/conformal/btcutil"
+	"github.com/conformal/btcutil/hdkeychain"
+	"github.com/conformal/btcwallet/waddrmgr"
+	"github.com/conformal/btcwallet/walletdb"
+)
+
+const (
+	minSeriesPubKeys = 3
+)
+
+// SeriesData represents a Series for a given Pool.
+type SeriesData struct {
+	version uint32
+	// Whether or not a series is active. This is serialized/deserialized but
+	// for now there's no way to deactivate a series.
+	active bool
+	// A.k.a. "m" in "m of n signatures needed".
+	reqSigs     uint32
+	publicKeys  []*hdkeychain.ExtendedKey
+	privateKeys []*hdkeychain.ExtendedKey
+}
+
+// Pool represents an arrangement of notary servers to securely
+// store and account for customer cryptocurrency deposits and to redeem
+// valid withdrawals. For details about how the arrangement works, see
+// http://opentransactions.org/wiki/index.php?title=Category:Voting_Pools
+type Pool struct {
+	ID           []byte
+	seriesLookup map[uint32]*SeriesData
+	manager      *waddrmgr.Manager
+	namespace    walletdb.Namespace
+}
+
+// Create creates a new entry in the database with the given ID
+// and returns the Pool representing it.
+func Create(namespace walletdb.Namespace, m *waddrmgr.Manager, poolID []byte) (*Pool, error) {
+	err := namespace.Update(
+		func(tx walletdb.Tx) error {
+			return putPool(tx, poolID)
+		})
+	if err != nil {
+		str := fmt.Sprintf("unable to add voting pool %v to db", poolID)
+		return nil, managerError(waddrmgr.ErrVotingPoolAlreadyExists, str, err)
+	}
+	return newPool(namespace, m, poolID), nil
+}
+
+// Load fetches the entry in the database with the given ID and returns the Pool
+// representing it.
+func Load(namespace walletdb.Namespace, m *waddrmgr.Manager, poolID []byte) (*Pool, error) {
+	err := namespace.View(
+		func(tx walletdb.Tx) error {
+			if exists := existsPool(tx, poolID); !exists {
+				str := fmt.Sprintf("unable to find voting pool %v in db", poolID)
+				return managerError(waddrmgr.ErrVotingPoolNotExists, str, nil)
+			}
+			return nil
+		})
+	if err != nil {
+		return nil, err
+	}
+	vp := newPool(namespace, m, poolID)
+	if err = vp.LoadAllSeries(); err != nil {
+		return nil, err
+	}
+	return vp, nil
+}
+
+// newPool creates a new Pool instance.
+func newPool(namespace walletdb.Namespace, m *waddrmgr.Manager, poolID []byte) *Pool {
+	return &Pool{
+		ID:           poolID,
+		seriesLookup: make(map[uint32]*SeriesData),
+		manager:      m,
+		namespace:    namespace,
+	}
+}
+
+// LoadAndGetDepositScript generates and returns a deposit script for the given seriesID,
+// branch and index of the Pool identified by poolID.
+func LoadAndGetDepositScript(namespace walletdb.Namespace, m *waddrmgr.Manager, poolID string, seriesID, branch, index uint32) ([]byte, error) {
+	pid := []byte(poolID)
+	vp, err := Load(namespace, m, pid)
+	if err != nil {
+		return nil, err
+	}
+	script, err := vp.DepositScript(seriesID, branch, index)
+	if err != nil {
+		return nil, err
+	}
+	return script, nil
+}
+
+// LoadAndCreateSeries loads the Pool with the given ID, creating a new one if it doesn't
+// yet exist, and then creates and returns a Series with the given seriesID, rawPubKeys
+// and reqSigs. See CreateSeries for the constraints enforced on rawPubKeys and reqSigs.
+func LoadAndCreateSeries(namespace walletdb.Namespace, m *waddrmgr.Manager, version uint32,
+	poolID string, seriesID, reqSigs uint32, rawPubKeys []string) error {
+	pid := []byte(poolID)
+	vp, err := Load(namespace, m, pid)
+	if err != nil {
+		managerErr := err.(waddrmgr.ManagerError)
+		if managerErr.ErrorCode == waddrmgr.ErrVotingPoolNotExists {
+			vp, err = Create(namespace, m, pid)
+			if err != nil {
+				return err
+			}
+		} else {
+			return err
+		}
+	}
+	return vp.CreateSeries(version, seriesID, reqSigs, rawPubKeys)
+}
+
+// LoadAndReplaceSeries loads the voting pool with the given ID and calls ReplaceSeries,
+// passing the given series ID, public keys and reqSigs to it.
+func LoadAndReplaceSeries(namespace walletdb.Namespace, m *waddrmgr.Manager, version uint32,
+	poolID string, seriesID, reqSigs uint32, rawPubKeys []string) error {
+	pid := []byte(poolID)
+	vp, err := Load(namespace, m, pid)
+	if err != nil {
+		return err
+	}
+	return vp.ReplaceSeries(version, seriesID, reqSigs, rawPubKeys)
+}
+
+// LoadAndEmpowerSeries loads the voting pool with the given ID and calls EmpowerSeries,
+// passing the given series ID and private key to it.
+func LoadAndEmpowerSeries(namespace walletdb.Namespace, m *waddrmgr.Manager,
+	poolID string, seriesID uint32, rawPrivKey string) error {
+	pid := []byte(poolID)
+	pool, err := Load(namespace, m, pid)
+	if err != nil {
+		return err
+	}
+	return pool.EmpowerSeries(seriesID, rawPrivKey)
+}
+
+// GetSeries returns the series with the given ID, or nil if it doesn't
+// exist.
+func (vp *Pool) GetSeries(seriesID uint32) *SeriesData {
+	series, exists := vp.seriesLookup[seriesID]
+	if !exists {
+		return nil
+	}
+	return series
+}
+
+// saveSeriesToDisk stores the given series ID and data in the database,
+// first encrypting the public/private extended keys.
+func (vp *Pool) saveSeriesToDisk(seriesID uint32, data *SeriesData) error {
+	var err error
+	encryptedPubKeys := make([][]byte, len(data.publicKeys))
+	for i, pubKey := range data.publicKeys {
+		encryptedPubKeys[i], err = vp.manager.Encrypt(
+			waddrmgr.CKTPublic, []byte(pubKey.String()))
+		if err != nil {
+			str := fmt.Sprintf("key %v failed encryption", pubKey)
+			return managerError(waddrmgr.ErrCrypto, str, err)
+		}
+	}
+	encryptedPrivKeys := make([][]byte, len(data.privateKeys))
+	for i, privKey := range data.privateKeys {
+		if privKey == nil {
+			encryptedPrivKeys[i] = nil
+		} else {
+			encryptedPrivKeys[i], err = vp.manager.Encrypt(
+				waddrmgr.CKTPrivate, []byte(privKey.String()))
+		}
+		if err != nil {
+			str := fmt.Sprintf("key %v failed encryption", privKey)
+			return managerError(waddrmgr.ErrCrypto, str, err)
+		}
+	}
+
+	err = vp.namespace.Update(func(tx walletdb.Tx) error {
+		return putSeries(tx, vp.ID, data.version, seriesID, data.active,
+			data.reqSigs, encryptedPubKeys, encryptedPrivKeys)
+	})
+	if err != nil {
+		str := fmt.Sprintf("cannot put series #%d into db", seriesID)
+		return managerError(waddrmgr.ErrSeriesStorage, str, err)
+	}
+	return nil
+}
+
+// CanonicalKeyOrder will return a copy of the input canonically
+// ordered which is defined to be lexicographical.
+func CanonicalKeyOrder(keys []string) []string {
+	orderedKeys := make([]string, len(keys))
+	copy(orderedKeys, keys)
+	sort.Sort(sort.StringSlice(orderedKeys))
+	return orderedKeys
+}
+
+// Convert the given slice of strings into a slice of ExtendedKeys,
+// checking that all of them are valid public (and not private) keys,
+// and that there are no duplicates.
+func convertAndValidatePubKeys(rawPubKeys []string) ([]*hdkeychain.ExtendedKey, error) {
+	seenKeys := make(map[string]bool)
+	keys := make([]*hdkeychain.ExtendedKey, len(rawPubKeys))
+	for i, rawPubKey := range rawPubKeys {
+		if _, seen := seenKeys[rawPubKey]; seen {
+			str := fmt.Sprintf("duplicated public key: %v", rawPubKey)
+			return nil, managerError(waddrmgr.ErrKeyDuplicate, str, nil)
+		}
+		seenKeys[rawPubKey] = true
+
+		key, err := hdkeychain.NewKeyFromString(rawPubKey)
+		if err != nil {
+			str := fmt.Sprintf("invalid extended public key %v", rawPubKey)
+			return nil, managerError(waddrmgr.ErrKeyChain, str, err)
+		}
+
+		if key.IsPrivate() {
+			str := fmt.Sprintf("private keys not accepted: %v", rawPubKey)
+			return nil, managerError(waddrmgr.ErrKeyIsPrivate, str, nil)
+		}
+		keys[i] = key
+	}
+	return keys, nil
+}
+
+// putSeries creates a new seriesData with the given arguments, ordering the
+// given public keys (using CanonicalKeyOrder), validating and converting them
+// to hdkeychain.ExtendedKeys, saves that to disk and adds it to this voting
+// pool's seriesLookup map. It also ensures inRawPubKeys has at least
+// minSeriesPubKeys items and reqSigs is not greater than the number of items in
+// inRawPubKeys.
+func (vp *Pool) putSeries(version, seriesID, reqSigs uint32, inRawPubKeys []string) error {
+	if len(inRawPubKeys) < minSeriesPubKeys {
+		str := fmt.Sprintf("need at least %d public keys to create a series", minSeriesPubKeys)
+		return managerError(waddrmgr.ErrTooFewPublicKeys, str, nil)
+	}
+
+	if reqSigs > uint32(len(inRawPubKeys)) {
+		str := fmt.Sprintf(
+			"the number of required signatures cannot be more than the number of keys")
+		return managerError(waddrmgr.ErrTooManyReqSignatures, str, nil)
+	}
+
+	rawPubKeys := CanonicalKeyOrder(inRawPubKeys)
+
+	keys, err := convertAndValidatePubKeys(rawPubKeys)
+	if err != nil {
+		return err
+	}
+
+	data := &SeriesData{
+		version:     version,
+		active:      false,
+		reqSigs:     reqSigs,
+		publicKeys:  keys,
+		privateKeys: make([]*hdkeychain.ExtendedKey, len(keys)),
+	}
+
+	err = vp.saveSeriesToDisk(seriesID, data)
+	if err != nil {
+		return err
+	}
+	vp.seriesLookup[seriesID] = data
+	return nil
+}
+
+// CreateSeries will create and return a new non-existing series.
+//
+// - rawPubKeys has to contain three or more public keys;
+// - reqSigs has to be less or equal than the number of public keys in rawPubKeys.
+func (vp *Pool) CreateSeries(version, seriesID, reqSigs uint32, rawPubKeys []string) error {
+	if series := vp.GetSeries(seriesID); series != nil {
+		str := fmt.Sprintf("series #%d already exists", seriesID)
+		return managerError(waddrmgr.ErrSeriesAlreadyExists, str, nil)
+	}
+
+	return vp.putSeries(version, seriesID, reqSigs, rawPubKeys)
+}
+
+// ReplaceSeries will replace an already existing series.
+//
+// - rawPubKeys has to contain three or more public keys
+// - reqSigs has to be less or equal than the number of public keys in rawPubKeys.
+func (vp *Pool) ReplaceSeries(version, seriesID, reqSigs uint32, rawPubKeys []string) error {
+	series := vp.GetSeries(seriesID)
+	if series == nil {
+		str := fmt.Sprintf("series #%d does not exist, cannot replace it", seriesID)
+		return managerError(waddrmgr.ErrSeriesNotExists, str, nil)
+	}
+
+	if series.IsEmpowered() {
+		str := fmt.Sprintf("series #%d has private keys and cannot be replaced", seriesID)
+		return managerError(waddrmgr.ErrSeriesAlreadyEmpowered, str, nil)
+	}
+
+	return vp.putSeries(version, seriesID, reqSigs, rawPubKeys)
+}
+
+// decryptExtendedKey uses Manager.Decrypt() to decrypt the encrypted byte slice and return
+// an extended (public or private) key representing it.
+func (vp *Pool) decryptExtendedKey(keyType waddrmgr.CryptoKeyType, encrypted []byte) (*hdkeychain.ExtendedKey, error) {
+	decrypted, err := vp.manager.Decrypt(keyType, encrypted)
+	if err != nil {
+		str := fmt.Sprintf("cannot decrypt key %v", encrypted)
+		return nil, managerError(waddrmgr.ErrCrypto, str, err)
+	}
+	result, err := hdkeychain.NewKeyFromString(string(decrypted))
+	zero(decrypted)
+	if err != nil {
+		str := fmt.Sprintf("cannot get key from string %v", decrypted)
+		return nil, managerError(waddrmgr.ErrKeyChain, str, err)
+	}
+	return result, nil
+}
+
+// validateAndDecryptSeriesKeys checks that the length of the public and private key
+// slices is the same, decrypts them, ensures the non-nil private keys have a matching
+// public key and returns them.
+func validateAndDecryptKeys(rawPubKeys, rawPrivKeys [][]byte, vp *Pool) (pubKeys, privKeys []*hdkeychain.ExtendedKey, err error) {
+	pubKeys = make([]*hdkeychain.ExtendedKey, len(rawPubKeys))
+	privKeys = make([]*hdkeychain.ExtendedKey, len(rawPrivKeys))
+	if len(pubKeys) != len(privKeys) {
+		return nil, nil, managerError(waddrmgr.ErrKeysPrivatePublicMismatch,
+			"the pub key and priv key arrays should have the same number of elements",
+			nil)
+	}
+
+	for i, encryptedPub := range rawPubKeys {
+		pubKey, err := vp.decryptExtendedKey(waddrmgr.CKTPublic, encryptedPub)
+		if err != nil {
+			return nil, nil, err
+		}
+		pubKeys[i] = pubKey
+
+		encryptedPriv := rawPrivKeys[i]
+		var privKey *hdkeychain.ExtendedKey
+		if encryptedPriv == nil {
+			privKey = nil
+		} else {
+			privKey, err = vp.decryptExtendedKey(waddrmgr.CKTPrivate, encryptedPriv)
+			if err != nil {
+				return nil, nil, err
+			}
+		}
+		privKeys[i] = privKey
+
+		if privKey != nil {
+			checkPubKey, err := privKey.Neuter()
+			if err != nil {
+				str := fmt.Sprintf("cannot neuter key %v", privKey)
+				return nil, nil, managerError(waddrmgr.ErrKeyNeuter, str, err)
+			}
+			if pubKey.String() != checkPubKey.String() {
+				str := fmt.Sprintf("public key %v different than expected %v",
+					pubKey, checkPubKey)
+				return nil, nil, managerError(waddrmgr.ErrKeyMismatch, str, nil)
+			}
+		}
+	}
+	return pubKeys, privKeys, nil
+}
+
+// LoadAllSeries fetches all series (decrypting their public and private
+// extended keys) for this Pool from the database and populates the
+// seriesLookup map with them. If there are any private extended keys for
+// a series, it will also ensure they have a matching extended public key
+// in that series.
+func (vp *Pool) LoadAllSeries() error {
+	var series map[uint32]*dbSeriesRow
+	err := vp.namespace.View(func(tx walletdb.Tx) error {
+		var err error
+		series, err = loadAllSeries(tx, vp.ID)
+		return err
+	})
+	if err != nil {
+		return err
+	}
+	for id, series := range series {
+		pubKeys, privKeys, err := validateAndDecryptKeys(
+			series.pubKeysEncrypted, series.privKeysEncrypted, vp)
+		if err != nil {
+			return err
+		}
+		vp.seriesLookup[id] = &SeriesData{
+			publicKeys:  pubKeys,
+			privateKeys: privKeys,
+			reqSigs:     series.reqSigs,
+		}
+	}
+	return nil
+}
+
+// existsSeries checks whether a series is stored in the database.
+// Used solely by the series creation test.
+func (vp *Pool) existsSeries(seriesID uint32) (bool, error) {
+	var exists bool
+	err := vp.namespace.View(
+		func(tx walletdb.Tx) error {
+			bucket := tx.RootBucket().Bucket(vp.ID)
+			if bucket == nil {
+				exists = false
+				return nil
+			}
+			exists = bucket.Get(uint32ToBytes(seriesID)) != nil
+			return nil
+		})
+	if err != nil {
+		return false, err
+	}
+	return exists, nil
+}
+
+// Change the order of the pubkeys based on branch number.
+// Given the three pubkeys ABC, this would mean:
+// - branch 0: CBA (reversed)
+// - branch 1: ABC (first key priority)
+// - branch 2: BAC (second key priority)
+// - branch 3: CAB (third key priority)
+func branchOrder(pks []*hdkeychain.ExtendedKey, branch uint32) ([]*hdkeychain.ExtendedKey, error) {
+	if pks == nil {
+		// This really shouldn't happen, but we want to be good citizens, so we
+		// return an error instead of crashing.
+		return nil, managerError(waddrmgr.ErrInvalidValue, "pks cannot be nil", nil)
+	}
+
+	if branch > uint32(len(pks)) {
+		return nil, managerError(waddrmgr.ErrInvalidBranch, "branch number is bigger than number of public keys", nil)
+	}
+
+	if branch == 0 {
+		numKeys := len(pks)
+		res := make([]*hdkeychain.ExtendedKey, numKeys)
+		copy(res, pks)
+		// reverse pk
+		for i, j := 0, numKeys-1; i < j; i, j = i+1, j-1 {
+			res[i], res[j] = res[j], res[i]
+		}
+		return res, nil
+	}
+
+	tmp := make([]*hdkeychain.ExtendedKey, len(pks))
+	tmp[0] = pks[branch-1]
+	j := 1
+	for i := 0; i < len(pks); i++ {
+		if i != int(branch-1) {
+			tmp[j] = pks[i]
+			j++
+		}
+	}
+	return tmp, nil
+}
+
+// DepositScriptAddress constructs a multi-signature redemption script using DepositScript
+// and returns the pay-to-script-hash-address for that script.
+func (vp *Pool) DepositScriptAddress(seriesID, branch, index uint32) (btcutil.Address, error) {
+	script, err := vp.DepositScript(seriesID, branch, index)
+	if err != nil {
+		return nil, err
+	}
+	scriptHash := btcutil.Hash160(script)
+
+	return btcutil.NewAddressScriptHashFromHash(scriptHash, vp.manager.Net())
+}
+
+// DepositScript constructs and returns a multi-signature redemption script where
+// a certain number (Series.reqSigs) of the public keys belonging to the series
+// with the given ID are required to sign the transaction for it to be successful.
+func (vp *Pool) DepositScript(seriesID, branch, index uint32) ([]byte, error) {
+	series := vp.GetSeries(seriesID)
+	if series == nil {
+		str := fmt.Sprintf("series #%d does not exist", seriesID)
+		return nil, managerError(waddrmgr.ErrSeriesNotExists, str, nil)
+	}
+
+	pubKeys, err := branchOrder(series.publicKeys, branch)
+	if err != nil {
+		return nil, err
+	}
+
+	pks := make([]*btcutil.AddressPubKey, len(pubKeys))
+	for i, key := range pubKeys {
+		child, err := key.Child(index)
+		// TODO: implement getting the next index until we find a valid one,
+		// in case there is a hdkeychain.ErrInvalidChild.
+		if err != nil {
+			str := fmt.Sprintf("child #%d for this pubkey %d does not exist", index, i)
+			return nil, managerError(waddrmgr.ErrKeyChain, str, err)
+		}
+		pubkey, err := child.ECPubKey()
+		if err != nil {
+			str := fmt.Sprintf("child #%d for this pubkey %d does not exist", index, i)
+			return nil, managerError(waddrmgr.ErrKeyChain, str, err)
+		}
+		pks[i], err = btcutil.NewAddressPubKey(pubkey.SerializeCompressed(), vp.manager.Net())
+		if err != nil {
+			str := fmt.Sprintf(
+				"child #%d for this pubkey %d could not be converted to an address",
+				index, i)
+			return nil, managerError(waddrmgr.ErrKeyChain, str, err)
+		}
+	}
+
+	script, err := btcscript.MultiSigScript(pks, int(series.reqSigs))
+	if err != nil {
+		str := fmt.Sprintf("error while making multisig script hash, %d", len(pks))
+		return nil, managerError(waddrmgr.ErrScriptCreation, str, err)
+	}
+
+	return script, nil
+}
+
+// EmpowerSeries adds the given extended private key (in raw format) to the
+// series with the given ID, thus allowing it to sign deposit/withdrawal
+// scripts. The series with the given ID must exist, the key must be a valid
+// private extended key and must match one of the series' extended public keys.
+func (vp *Pool) EmpowerSeries(seriesID uint32, rawPrivKey string) error {
+	// make sure this series exists
+	series := vp.GetSeries(seriesID)
+	if series == nil {
+		str := fmt.Sprintf("series %d does not exist for this voting pool",
+			seriesID)
+		return managerError(waddrmgr.ErrSeriesNotExists, str, nil)
+	}
+
+	// Check that the private key is valid.
+	privKey, err := hdkeychain.NewKeyFromString(rawPrivKey)
+	if err != nil {
+		str := fmt.Sprintf("invalid extended private key %v", rawPrivKey)
+		return managerError(waddrmgr.ErrKeyChain, str, err)
+	}
+	if !privKey.IsPrivate() {
+		str := fmt.Sprintf(
+			"to empower a series you need the extended private key, not an extended public key %v",
+			privKey)
+		return managerError(waddrmgr.ErrKeyIsPublic, str, err)
+	}
+
+	pubKey, err := privKey.Neuter()
+	if err != nil {
+		str := fmt.Sprintf("invalid extended private key %v, can't convert to public key",
+			rawPrivKey)
+		return managerError(waddrmgr.ErrKeyNeuter, str, err)
+	}
+
+	lookingFor := pubKey.String()
+	found := false
+
+	// Make sure the private key has the corresponding public key in the series,
+	// to be able to empower it.
+	for i, publicKey := range series.publicKeys {
+		if publicKey.String() == lookingFor {
+			found = true
+			series.privateKeys[i] = privKey
+		}
+	}
+
+	if !found {
+		str := fmt.Sprintf(
+			"private Key does not have a corresponding public key in this series")
+		return managerError(waddrmgr.ErrKeysPrivatePublicMismatch, str, nil)
+	}
+
+	err = vp.saveSeriesToDisk(seriesID, series)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// IsEmpowered returns true if this series is empowered (i.e. if it has
+// at least one private key loaded).
+func (s *SeriesData) IsEmpowered() bool {
+	for _, key := range s.privateKeys {
+		if key != nil {
+			return true
+		}
+	}
+	return false
+}
+
+// managerError creates a waddrmgr.ManagerError given a set of arguments.
+// XXX(lars): We should probably make our own votingpoolError function.
+func managerError(c waddrmgr.ErrorCode, desc string, err error) waddrmgr.ManagerError {
+	return waddrmgr.ManagerError{ErrorCode: c, Description: desc, Err: err}
+}
+
+// zero sets all bytes in the passed slice to zero.  This is used to
+// explicitly clear private key material from memory.
+//
+// XXX(lars) there exists currently around 4-5 other zero functions
+// with at least 3 different implementations. We should try to
+// consolidate these.
+func zero(b []byte) {
+	for i := range b {
+		b[i] ^= b[i]
+	}
+}
--- a/votingpool/pool_test.go
+++ b/votingpool/pool_test.go
--- a/votingpool/test_coverage.txt
+++ b/votingpool/test_coverage.txt
@ -0,0 +1,92 @@
+
+github.com/conformal/btcwallet/votingpool/db.go			 serializeSeriesRow			 100.00% (29/29)
+github.com/conformal/btcwallet/votingpool/pool.go		 branchOrder				 100.00% (19/19)
+github.com/conformal/btcwallet/votingpool/pool.go		 convertAndValidatePubKeys		 100.00% (16/16)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Credits.Less				 100.00% (12/12)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.decryptExtendedKey		 100.00% (10/10)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.ReplaceSeries			 100.00% (8/8)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 AddressRange.NumAddresses		 100.00% (7/7)
+github.com/conformal/btcwallet/votingpool/pool.go		 Create					 100.00% (5/5)
+github.com/conformal/btcwallet/votingpool/db.go			 putPool				 100.00% (5/5)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.DepositScriptAddress		 100.00% (5/5)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 currentTx.addTxIn			 100.00% (4/4)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 currentTx.addTxOut			 100.00% (4/4)
+github.com/conformal/btcwallet/votingpool/pool.go		 CanonicalKeyOrder			 100.00% (4/4)
+github.com/conformal/btcwallet/votingpool/pool.go		 @81:3					 100.00% (4/4)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.GetSeries				 100.00% (4/4)
+github.com/conformal/btcwallet/votingpool/pool.go		 seriesData.IsEmpowered			 100.00% (4/4)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.CreateSeries			 100.00% (4/4)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.existsSeries			 100.00% (3/3)
+github.com/conformal/btcwallet/votingpool/db.go			 uint32ToBytes				 100.00% (3/3)
+github.com/conformal/btcwallet/votingpool/pool.go		 @398:27				 100.00% (3/3)
+github.com/conformal/btcwallet/votingpool/pool.go		 zero					 100.00% (2/2)
+github.com/conformal/btcwallet/votingpool/db.go			 putSeries				 100.00% (2/2)
+github.com/conformal/btcwallet/votingpool/db.go			 existsPool				 100.00% (2/2)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 Ntxid					 100.00% (2/2)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 NewOutputRequest			 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 votingPoolAddress.Index		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 init					 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 estimateSize				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 calculateFee				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/db.go			 bytesToUint32				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 currentTx.isTooBig			 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/error.go		 newError				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Credit.TxSha				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Credit.OutputIndex			 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Credit.Address				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 newCredit				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Credits.Len				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Credits.Swap				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 WithdrawalOutput.Outpoints		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 WithdrawalOutput.Address		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Pool.isCharterOutput			 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/pool.go		 @67:3					 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/pool.go		 newPool				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 WithdrawalOutput.Status		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 WithdrawalOutput.addOutpoint		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 WithdrawalStatus.Outputs		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 WithdrawalOutput.Amount		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 ChangeAddress.Next			 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/pool.go		 @205:28				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 votingPoolAddress.Addr			 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 votingPoolAddress.SeriesID		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/pool.go		 managerError				 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 votingPoolAddress.Branch		 100.00% (1/1)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.EmpowerSeries			 96.43% (27/28)
+github.com/conformal/btcwallet/votingpool/db.go			 deserializeSeriesRow			 94.87% (37/39)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.putSeries				 93.75% (15/16)
+github.com/conformal/btcwallet/votingpool/pool.go		 validateAndDecryptKeys			 92.31% (24/26)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Pool.getEligibleInputsFromSeries	 86.36% (19/22)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Pool.getEligibleInputs			 85.71% (6/7)
+github.com/conformal/btcwallet/votingpool/pool.go		 Load					 85.71% (6/7)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 Pool.isCreditEligible			 85.71% (6/7)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 withdrawal.finalizeCurrentTx		 84.21% (16/19)
+github.com/conformal/btcwallet/votingpool/input_selection.go	 groupCreditsByAddr			 83.33% (10/12)
+github.com/conformal/btcwallet/votingpool/db.go			 loadAllSeries				 83.33% (5/6)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 Pool.ChangeAddress			 83.33% (5/6)
+github.com/conformal/btcwallet/votingpool/pool.go		 LoadAndCreateSeries			 80.00% (8/10)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.LoadAllSeries			 80.00% (8/10)
+github.com/conformal/btcwallet/votingpool/pool.go		 LoadAndEmpowerSeries			 80.00% (4/5)
+github.com/conformal/btcwallet/votingpool/pool.go		 LoadAndReplaceSeries			 80.00% (4/5)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 Pool.WithdrawalAddress			 80.00% (4/5)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 withdrawal.sign			 75.76% (25/33)
+github.com/conformal/btcwallet/votingpool/pool.go		 LoadAndGetDepositScript		 75.00% (6/8)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 OutputRequest.pkScript			 75.00% (3/4)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.DepositScript			 73.08% (19/26)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 ValidateSigScripts			 72.73% (8/11)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 withdrawal.fulfilNextOutput		 72.41% (21/29)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 SignMultiSigUTXO			 71.43% (15/21)
+github.com/conformal/btcwallet/votingpool/db.go			 @77:3					 71.43% (5/7)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 getRedeemScript			 71.43% (5/7)
+github.com/conformal/btcwallet/votingpool/pool.go		 Pool.saveSeriesToDisk			 70.00% (14/20)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 withdrawal.fulfilOutputs		 70.00% (7/10)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 getPrivKey				 70.00% (7/10)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 Pool.Withdrawal			 66.67% (12/18)
+github.com/conformal/btcwallet/votingpool/pool.go		 @426:3					 66.67% (4/6)
+github.com/conformal/btcwallet/votingpool/error.go		 ErrorCode.String			 66.67% (2/3)
+github.com/conformal/btcwallet/votingpool/db.go			 putSeriesRow				 53.85% (7/13)
+github.com/conformal/btcwallet/votingpool/error.go		 Error.Error				 0.00% (0/3)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 withdrawal.updateStatusFor		 0.00% (0/0)
+github.com/conformal/btcwallet/votingpool/withdrawal.go		 currentTx.rollBackLastOutput		 0.00% (0/0)
+github.com/conformal/btcwallet/votingpool			 --------------------------------	 85.36% (554/649)
+
--- a/waddrmgr/address.go
+++ b/waddrmgr/address.go
@ -125,7 +125,7 @@ type managedAddress struct {
 	privKeyMutex     sync.Mutex
 }

-// Enforce mangedAddress satisfies the ManagedPubKeyAddress interface.
+// Enforce managedAddress satisfies the ManagedPubKeyAddress interface.
 var _ ManagedPubKeyAddress = (*managedAddress)(nil)

 // unlock decrypts and stores a pointer to the associated private key.  It will
--- a/waddrmgr/db.go
+++ b/waddrmgr/db.go
@ -302,17 +302,17 @@ func putWatchingOnly(tx walletdb.Tx, watchingOnly bool) error {
 	}

 	if err := bucket.Put(watchingOnlyName, []byte{encoded}); err != nil {
-		str := "failed to store wathcing only flag"
+		str := "failed to store watching only flag"
 		return managerError(ErrDatabase, str, err)
 	}
 	return nil
 }

-// accountKey returns the account key to use in the database for a given account
-// number.
-func accountKey(account uint32) []byte {
+// uint32ToBytes converts a 32 bit unsigned integer into a 4-byte slice in
+// little-endian order: 1 -> [1 0 0 0].
+func uint32ToBytes(number uint32) []byte {
 	buf := make([]byte, 4)
-	binary.LittleEndian.PutUint32(buf, account)
+	binary.LittleEndian.PutUint32(buf, number)
 	return buf
 }

@ -404,7 +404,6 @@ func deserializeBIP0044AccountRow(accountID []byte, row *dbAccountRow) (*dbBIP00
 func serializeBIP0044AccountRow(encryptedPubKey,
 	encryptedPrivKey []byte, nextExternalIndex, nextInternalIndex uint32,
 	name string) []byte {
-
 	// The serialized BIP0044 account raw data format is:
 	//   <encpubkeylen><encpubkey><encprivkeylen><encprivkey><nextextidx>
 	//   <nextintidx><namelen><name>
@ -438,7 +437,7 @@ func serializeBIP0044AccountRow(encryptedPubKey,
 func fetchAccountInfo(tx walletdb.Tx, account uint32) (interface{}, error) {
 	bucket := tx.RootBucket().Bucket(acctBucketName)

-	accountID := accountKey(account)
+	accountID := uint32ToBytes(account)
 	serializedRow := bucket.Get(accountID)
 	if serializedRow == nil {
 		str := fmt.Sprintf("account %d not found", account)
@ -465,7 +464,7 @@ func putAccountRow(tx walletdb.Tx, account uint32, row *dbAccountRow) error {
 	bucket := tx.RootBucket().Bucket(acctBucketName)

 	// Write the serialized value keyed by the account number.
-	err := bucket.Put(accountKey(account), serializeAccountRow(row))
+	err := bucket.Put(uint32ToBytes(account), serializeAccountRow(row))
 	if err != nil {
 		str := fmt.Sprintf("failed to store account %d", account)
 		return managerError(ErrDatabase, str, err)
@ -781,12 +780,13 @@ func putChainedAddress(tx walletdb.Tx, addressID []byte, account uint32,

 	// Update the next index for the appropriate internal or external
 	// branch.
-	accountID := accountKey(account)
+	accountID := uint32ToBytes(account)
 	bucket := tx.RootBucket().Bucket(acctBucketName)
 	serializedAccount := bucket.Get(accountID)

 	// Deserialize the account row.
 	row, err := deserializeAccountRow(accountID, serializedAccount)
+
 	if err != nil {
 		return err
 	}
@ -1228,7 +1228,7 @@ func upgradeManager(namespace walletdb.Namespace) error {
 			return managerError(ErrDatabase, str, err)
 		}

-		// Save the most recent manager version if it isn't already
+		// Save the most recent database version if it isn't already
 		// there, otherwise keep track of it for potential upgrades.
 		verBytes := mainBucket.Get(mgrVersionName)
 		if verBytes == nil {
--- a/waddrmgr/doc.go
+++ b/waddrmgr/doc.go
@ -117,7 +117,7 @@ Requesting Existing Addresses

 In addition to generating new addresses, access to old addresses is often
 required.  Most notably, to sign transactions in order to redeem them.  The
-Address function provides this capability and returns a ManagedAddress
+Address function provides this capability and returns a ManagedAddress.

 Importing Addresses

--- a/waddrmgr/error.go
+++ b/waddrmgr/error.go
@ -58,7 +58,7 @@ const (
 	ErrDatabase ErrorCode = iota

 	// ErrKeyChain indicates an error with the key chain typically either
-	// due to the inability to create and extended key or deriving a child
+	// due to the inability to create an extended key or deriving a child
 	// extended key.  When this error code is set, the Err field of the
 	// ManagerError will be set to the underlying error.
 	ErrKeyChain
@ -74,54 +74,54 @@ const (
 	// key type has been selected.
 	ErrInvalidKeyType

-	// ErrNoExist indicates the manager does not exist.
+	// ErrNoExist indicates that the specified database does not exist.
 	ErrNoExist

-	// ErrAlreadyExists indicates the specified manager already exists.
+	// ErrAlreadyExists indicates that the specified database already exists.
 	ErrAlreadyExists

-	// ErrCoinTypeTooHigh indicates the coin type specified in the provided
+	// ErrCoinTypeTooHigh indicates that the coin type specified in the provided
 	// network parameters is higher than the max allowed value as defined
 	// by the maxCoinType constant.
 	ErrCoinTypeTooHigh

-	// ErrAccountNumTooHigh indicates the specified account number is higher
+	// ErrAccountNumTooHigh indicates that the specified account number is higher
 	// than the max allowed value as defined by the MaxAccountNum constant.
 	ErrAccountNumTooHigh

-	// ErrLocked indicates the an operation which requires the address
-	// manager to be unlocked was requested on a locked address manager.
+	// ErrLocked indicates that an operation, which requires the account
+	// manager to be unlocked, was requested on a locked account manager.
 	ErrLocked

-	// ErrWatchingOnly indicates the an operation which requires the address
-	// manager to have access to private data was requested on a
-	// watching-only address manager.
+	// ErrWatchingOnly indicates that an operation, which requires the
+	// account manager to have access to private data, was requested on
+	// a watching-only account manager.
 	ErrWatchingOnly

-	// ErrInvalidAccount indicates the requested account is not valid.
+	// ErrInvalidAccount indicates that the requested account is not valid.
 	ErrInvalidAccount

-	// ErrAddressNotFound indicates the requested address is not known to
-	// the address manager.
+	// ErrAddressNotFound indicates that the requested address is not known to
+	// the account manager.
 	ErrAddressNotFound

-	// ErrAccountNotFound indicates the requested account is not known to
-	// the address manager.
+	// ErrAccountNotFound indicates that the requested account is not known to
+	// the account manager.
 	ErrAccountNotFound

-	// ErrDuplicate indicates an address already exists.
+	// ErrDuplicate indicates that an address already exists.
 	ErrDuplicate

-	// ErrTooManyAddresses indicates more than the maximum allowed number of
+	// ErrTooManyAddresses indicates that more than the maximum allowed number of
 	// addresses per account have been requested.
 	ErrTooManyAddresses

-	// ErrWrongPassphrase inidicates the specified password is incorrect.
-	// This could be for either the public and private master keys.
+	// ErrWrongPassphrase indicates that the specified passphrase is incorrect.
+	// This could be for either public or private master keys.
 	ErrWrongPassphrase

-	// ErrWrongNet indicates the private key to be imported is not for the
-	// the same network the account mangaer is configured for.
+	// ErrWrongNet indicates that the private key to be imported is not for the
+	// the same network the account manager is configured for.
 	ErrWrongNet
 )

@ -144,6 +144,26 @@ var errorCodeStrings = map[ErrorCode]string{
 	ErrTooManyAddresses:  "ErrTooManyAddresses",
 	ErrWrongPassphrase:   "ErrWrongPassphrase",
 	ErrWrongNet:          "ErrWrongNet",
+
+	// The following error codes are defined in pool_error.go.
+	ErrSeriesStorage:             "ErrSeriesStorage",
+	ErrSeriesVersion:             "ErrSeriesVersion",
+	ErrSeriesNotExists:           "ErrSeriesNotExists",
+	ErrSeriesAlreadyExists:       "ErrSeriesAlreadyExists",
+	ErrSeriesAlreadyEmpowered:    "ErrSeriesAlreadyEmpowered",
+	ErrKeyIsPrivate:              "ErrKeyIsPrivate",
+	ErrKeyIsPublic:               "ErrKeyIsPublic",
+	ErrKeyNeuter:                 "ErrKeyNeuter",
+	ErrKeyMismatch:               "ErrKeyMismatch",
+	ErrKeysPrivatePublicMismatch: "ErrKeysPrivatePublicMismatch",
+	ErrKeyDuplicate:              "ErrKeyDuplicate",
+	ErrTooFewPublicKeys:          "ErrTooFewPublicKeys",
+	ErrVotingPoolAlreadyExists:   "ErrVotingPoolAlreadyExists",
+	ErrVotingPoolNotExists:       "ErrVotingPoolNotExists",
+	ErrScriptCreation:            "ErrScriptCreation",
+	ErrTooManyReqSignatures:      "ErrTooManyReqSignatures",
+	ErrInvalidBranch:             "ErrInvalidBranch",
+	ErrInvalidValue:              "ErrInvalidValue",
 }

 // String returns the ErrorCode as a human-readable name.
--- a/waddrmgr/error_test.go
+++ b/waddrmgr/error_test.go
@ -46,6 +46,22 @@ func TestErrorCodeStringer(t *testing.T) {
 		{waddrmgr.ErrTooManyAddresses, "ErrTooManyAddresses"},
 		{waddrmgr.ErrWrongPassphrase, "ErrWrongPassphrase"},
 		{waddrmgr.ErrWrongNet, "ErrWrongNet"},
+
+		// The following error codes are defined in pool_error.go.
+		{waddrmgr.ErrSeriesStorage, "ErrSeriesStorage"},
+		{waddrmgr.ErrSeriesNotExists, "ErrSeriesNotExists"},
+		{waddrmgr.ErrSeriesAlreadyExists, "ErrSeriesAlreadyExists"},
+		{waddrmgr.ErrSeriesAlreadyEmpowered, "ErrSeriesAlreadyEmpowered"},
+		{waddrmgr.ErrKeyIsPrivate, "ErrKeyIsPrivate"},
+		{waddrmgr.ErrKeyNeuter, "ErrKeyNeuter"},
+		{waddrmgr.ErrKeyMismatch, "ErrKeyMismatch"},
+		{waddrmgr.ErrKeysPrivatePublicMismatch, "ErrKeysPrivatePublicMismatch"},
+		{waddrmgr.ErrKeyDuplicate, "ErrKeyDuplicate"},
+		{waddrmgr.ErrTooFewPublicKeys, "ErrTooFewPublicKeys"},
+		{waddrmgr.ErrVotingPoolNotExists, "ErrVotingPoolNotExists"},
+		{waddrmgr.ErrScriptCreation, "ErrScriptCreation"},
+		{waddrmgr.ErrTooManyReqSignatures, "ErrTooManyReqSignatures"},
+
 		{0xffff, "Unknown ErrorCode (65535)"},
 	}
 	t.Logf("Running %d tests", len(tests))
--- a/waddrmgr/internal_test.go
+++ b/waddrmgr/internal_test.go
@ -47,7 +47,7 @@ func TstRunWithReplacedNewSecretKey(callback func()) {
 	callback()
 }

-// TstCheckPublicPassphrase return true if the provided public passphrase is
+// TstCheckPublicPassphrase returns true if the provided public passphrase is
 // correct for the manager.
 func (m *Manager) TstCheckPublicPassphrase(pubPassphrase []byte) bool {
 	secretKey := snacl.SecretKey{Key: &snacl.CryptoKey{}}
--- a/waddrmgr/pool_error.go
+++ b/waddrmgr/pool_error.go
@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2014 Conformal Systems LLC <info@conformal.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+package waddrmgr
+
+// XXX: All errors defined here will soon be moved to the votingpool package, where they
+// belong.
+
+// Constants that identify voting pool-related errors.
+// The codes start from 1000 to avoid confusion with the ones in error.go.
+const (
+	// ErrSeriesStorage indicates that an error occurred while serializing
+	// or deserializing one or more series for storing into database.
+	ErrSeriesStorage ErrorCode = iota + 1000
+
+	// ErrSeriesVersion indicates that we've been asked to deal with
+	// a series whose version is unsupported
+	ErrSeriesVersion
+
+	// ErrSeriesNotExists indicates that an attempt has been made to access
+	// a series that does not exist.
+	ErrSeriesNotExists
+
+	// ErrSeriesAlreadyExists indicates that an attempt has been made to create
+	// a series that already exists.
+	ErrSeriesAlreadyExists
+
+	// ErrSeriesAlreadyEmpowered indicates that an already empowered series
+	// was used where a not empowered one was expected.
+	ErrSeriesAlreadyEmpowered
+
+	// ErrKeyIsPrivate indicates that a private key was used where a public
+	// one was expected.
+	ErrKeyIsPrivate
+
+	// ErrKeyIsPublic indicates that a public key was used where a private
+	// one was expected.
+	ErrKeyIsPublic
+
+	// ErrKeyNeuter indicates a problem when trying to neuter a private key.
+	ErrKeyNeuter
+
+	// ErrKeyMismatch indicates that the key is not the expected one.
+	ErrKeyMismatch
+
+	// ErrKeysPrivatePublicMismatch indicates that the number of private and
+	// public keys is not the same.
+	ErrKeysPrivatePublicMismatch
+
+	// ErrKeyDuplicate indicates that a key is duplicated.
+	ErrKeyDuplicate
+
+	// ErrTooFewPublicKeys indicates that a required minimum of public
+	// keys was not met.
+	ErrTooFewPublicKeys
+
+	// ErrVotingPoolAlreadyExists indicates that an attempt has been made to
+	// create a voting pool that already exists.
+	ErrVotingPoolAlreadyExists
+
+	// ErrVotingPoolNotExists indicates that an attempt has been made to access
+	// a voting pool that does not exist.
+	ErrVotingPoolNotExists
+
+	// ErrScriptCreation indicates that the creation of a deposit script failed.
+	ErrScriptCreation
+
+	// ErrTooManyReqSignatures indicates that too many required
+	// signatures are requested.
+	ErrTooManyReqSignatures
+
+	// ErrInvalidBranch indicates that the given branch number is not valid
+	// for a given set of public keys.
+	ErrInvalidBranch
+
+	// ErrInvalidValue indicates that the value of a given function argument
+	// is invalid.
+	ErrInvalidValue
+)