Skip to content

Latest commit

 

History

History

sage-impl

README.md

hash-to-curve proof-of-concept implementations in Sage

This directory contains a Sage implementation of the BLS signatures draft.

Note: this implementation supports only signing, not verifying signatures. It can be used to generate signatures for testing against the Python and Rust implementations.

(This is mostly because Sage has known performance issues with field extension towers. It should be possible with a bit of effort to sidestep these issues, but I have not yet put in the work to do so. Sorry!)

prerequisites

You will need SageMath (tested with 8.7) and Make to run this code.

usage

There are four utilities: bls_sig_g1.sage, bls_sig_g2.sage, opt_sswu_g1.sage, and opt_sswu_g2.sage.

To get started, you must precompile the .sage files:

make pyfiles

after which you can execute any of the four programs.

opt_sswu_g1.sage and opt_sswu_g2.sage hash messages to G1 and G2, respectively.

sage opt_sswu_g1.sage [-d] [-T test_input_file] [msg ...]

bls_sig_g1.sage and bls_sig_g2.sage sign messages in G1 and G2, respectively.

sage bls_sig_g1.sage [-d] [-T test_input_file] [-k secret_key] [msg ...]

  • -d enables verbose debug output.

  • -T can be used multiple times to specify test input files (see ../test_vectors).

  • -k sets the secret key to be used when signing messages from the commandline.

  • -g enables (machine-readable) test vector generation mode

  • When signing, -B, -A, and -P select Basic, Augmented, or Proof-of-possession signatures. The default is Basic.

  • All other arguments are interpreted as messages to be hashed or signed.

You can also use the sig_g1, sig_g2, hash_g1, and hash_g2 Makefile targets, e.g.,

make hash_g2
make sig_g1 TEST_INPUTS=fips_186_3_P256 DEBUG=1

These targets invoke the appropriate script and save the results to a log file. There are two relevant commandline flags for these targets:

  • TEST_INPUTS= defaults to rfc6979. No supplied path is necessary.

  • DEBUG= defaults to 0; 1 enables the -d switch.

license

See the license in the toplevel directory of this repository.