quorum-code/crypto/ecies

# NOTE

This implementation is direct fork of Kylom's implementation. I claim no authorship over this code apart from some minor modifications.
Please be aware this code **has not yet been reviewed**.

ecies implements the Elliptic Curve Integrated Encryption Scheme.

The package is designed to be compliant with the appropriate NIST
standards, and therefore doesn't support the full SEC 1 algorithm set.


STATUS:

ecies should be ready for use. The ASN.1 support is only complete so
far as to supported the listed algorithms before.


CAVEATS

1. CMAC support is currently not present.


SUPPORTED ALGORITHMS

SYMMETRIC CIPHERS HASH FUNCTIONS
AES128 SHA-1
AES192 SHA-224
AES256 SHA-256
SHA-384
ELLIPTIC CURVE SHA-512
P256
P384 KEY DERIVATION FUNCTION
P521 NIST SP 800-65a Concatenation KDF

Curve P224 isn't supported because it does not provide a minimum security
level of AES128 with HMAC-SHA1. According to NIST SP 800-57, the security
level of P224 is 112 bits of security. Symmetric ciphers use CTR-mode;
message tags are computed using HMAC- function.


CURVE SELECTION

According to NIST SP 800-57, the following curves should be selected:

+----------------+-------+
| SYMMETRIC SIZE | CURVE |
+----------------+-------+
| 128-bit | P256 |
+----------------+-------+
| 192-bit | P384 |
+----------------+-------+
| 256-bit | P521 |
+----------------+-------+


TODO

1. Look at serialising the parameters with the SEC 1 ASN.1 module.
2. Validate ASN.1 formats with SEC 1.


TEST VECTORS

The only test vectors I've found so far date from 1993, predating AES
and including only 163-bit curves. Therefore, there are no published
test vectors to compare to.


LICENSE

ecies is released under the same license as the Go source code. See the
LICENSE file for details.


REFERENCES

* SEC (Standard for Efficient Cryptography) 1, version 2.0: Elliptic
Curve Cryptography; Certicom, May 2009.
http://www.secg.org/sec1-v2.pdf
* GEC (Guidelines for Efficient Cryptography) 2, version 0.3: Test
Vectors for SEC 1; Certicom, September 1999.
http://read.pudn.com/downloads168/doc/772358/TestVectorsforSEC%201-gec2.pdf
* NIST SP 800-56a: Recommendation for Pair-Wise Key Establishment Schemes
Using Discrete Logarithm Cryptography. National Institute of Standards
and Technology, May 2007.
http://csrc.nist.gov/publications/nistpubs/800-56A/SP800-56A_Revision1_Mar08-2007.pdf
* Suite B Implementer’s Guide to NIST SP 800-56A. National Security
Agency, July 28, 2009.
http://www.nsa.gov/ia/_files/SuiteB_Implementer_G-113808.pdf
* NIST SP 800-57: Recommendation for Key Management – Part 1: General
(Revision 3). National Institute of Standards and Technology, July
2012.
http://csrc.nist.gov/publications/nistpubs/800-57/sp800-57_part1_rev3_general.pdf