c7d523f83c
This commit optimizes the decompressPoint subroutine, used in extracting compressed pubkeys and performing pubkey recovery. We do so by replacing the use of big.Int.Exp with with square-and-multiply exponentiation of btcec's more optimized fieldVals, reducing the overall latency and memory requirements of decompressPoint. Instead of operating on bits of Q = (P+1)/4, the exponentiation applies the square-and-multiply operations on full bytes of Q. Compared to the original speedup. Compared the bit-wise version, the improvement is roughly 10%. A new pair fieldVal methods called Sqrt and SqrtVal are added, which applies the square-and-multiply exponentiation using precomputed byte-slice of the value Q. Comparison against big.Int sqrt and SAM sqrt over bytes of Q: benchmark old ns/op new ns/op delta BenchmarkParseCompressedPubKey-8 35545 23119 -34.96% benchmark old allocs new allocs delta BenchmarkParseCompressedPubKey-8 35 6 -82.86% benchmark old bytes new bytes delta BenchmarkParseCompressedPubKey-8 2777 256 -90.78% |
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|---|---|---|
| .. | ||
| bench_test.go | ||
| btcec.go | ||
| btcec_test.go | ||
| ciphering.go | ||
| ciphering_test.go | ||
| doc.go | ||
| example_test.go | ||
| field.go | ||
| field_test.go | ||
| genprecomps.go | ||
| gensecp256k1.go | ||
| precompute.go | ||
| privkey.go | ||
| privkey_test.go | ||
| pubkey.go | ||
| pubkey_test.go | ||
| README.md | ||
| secp256k1.go | ||
| signature.go | ||
| signature_test.go | ||
btcec
Package btcec implements elliptic curve cryptography needed for working with Bitcoin (secp256k1 only for now). It is designed so that it may be used with the standard crypto/ecdsa packages provided with go. A comprehensive suite of test is provided to ensure proper functionality. Package btcec was originally based on work from ThePiachu which is licensed under the same terms as Go, but it has signficantly diverged since then. The btcsuite developers original is licensed under the liberal ISC license.
Although this package was primarily written for btcd, it has intentionally been designed so it can be used as a standalone package for any projects needing to use secp256k1 elliptic curve cryptography.
Installation and Updating
$ go get -u github.com/btcsuite/btcd/btcec
Examples
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Sign Message
Demonstrates signing a message with a secp256k1 private key that is first parsed form raw bytes and serializing the generated signature. -
Verify Signature
Demonstrates verifying a secp256k1 signature against a public key that is first parsed from raw bytes. The signature is also parsed from raw bytes. -
Encryption Demonstrates encrypting a message for a public key that is first parsed from raw bytes, then decrypting it using the corresponding private key.
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Decryption Demonstrates decrypting a message using a private key that is first parsed from raw bytes.
GPG Verification Key
All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from the btcsuite developers. To verify the signature perform the following:
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Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt
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Import the public key into your GPG keyring:
gpg --import GIT-GPG-KEY-conformal.txt -
Verify the release tag with the following command where
TAG_NAMEis a placeholder for the specific tag:git tag -v TAG_NAME
License
Package btcec is licensed under the copyfree ISC License except for btcec.go and btcec_test.go which is under the same license as Go.