package bls12381
Install
Dune Dependency
Authors
Maintainers
Sources
md5=6888479cbebb02f68b137d4bcc3a6488
sha512=f5395e1461cb5edba0e7072ca90c64bed50ae45b53fe76f4f071043f1b56f3967495c939757abe5307aa9d84b4bf33bd98e5a4c465016a42da4b4570d4503234
Description
Published: 13 Jan 2023
README
OCaml implementation of BLS12381
This library provides a fast implementation of:
operations over the scalar field, including (i)FFT.
operations over the groups G1 and G2, including ECFFT, hash_to_curve as described in this specification and the pippenger algorithm for fast multi scalar exponentiation.
operations over the target group of the pairing (GT), written additively.
pairing from G1 x G2 to GT
Encoding
Scalar
The scalar field is Fr = GF(0x73eda753299d7d483339d80809a1d80553bda402fffe5bfeffffffff00000001)
, encoded on 32 bytes in little endian.
Groups
For G1, the base field is Fq: GF(0x1a0111ea397fe69a4b1ba7b6434bacd764774b84f38512bf6730d2a0f6b0f6241eabfffeb153ffffb9feffffffffaaab
) and E(Fq) := y^2 = x^3 + 4
. An element of the base field can be encoded on 48 bytes (using only 381 bits, leaving 3 bits unused).
For G2, the base field is Fq2 := Fq[Z]/(X^2 + 1)
and E(Fq2) := y^2 = x^3 + 4 (Z + 1)
. An element of the base field can be encoded on 2 * 48 bytes representing each coefficient of the polynomial. 3 bits of each coefficient encoding are unused.
The « uncompressed » form (x, y)
of G1 and G2 is the concatenation of the elements x
and y
encoded in big endian.
The « compressed » form uses the first 3 most significant (and unused) bits of the coordinate x
.
the first most significant bit is always set to
1
to carry the information it is the compressed encoding of a point.the second most significant bit is set to
1
if the element is the identity of the curve.the third most significant bit is the sign of
y
. It is set to1
ify
is lexicographically larger thany
.
Install
opam install bls12381
By default, if the architecture supports ADX, bls12381
with be compiled using ADX opcodes (giving optimisations up to 20% for some arithmetic operations). If you don't want to build using ADX, you can add the environment variable BLST_PORTABLE
and set it to any value. For instance,
BLST_PORTABLE=y opam install bls12381
will instruct to build bls12381 without ADX. This might be useful if you build docker images on ADX machines but you need the image to be portable on architecture not supporting ADX.
If the architecture does not support ADX, bls12381
will be compiled without ADX opcodes.
Run tests
dune runtest
To get the coverage:
dune runtest instrumentwith bisect_ppx force
bisectppxreport html
Run the benchmarks
Install core_bench
:
opam install core_bench
See files listed in the directory benchmark
and execute it with dune exec
. For instance:
dune exec ./benchmark/bench_fr.exe
Documentation
opam install odoc
dune build @doc
Dependencies (6)
Dev Dependencies (5)

odoc
withdoc

ffpbt
>= "0.6.0" & < "0.7.0" & withtest

integers_stubs_js
withtest

alcotest
withtest

zarith_stubs_js
withtest
Used by (6)

bls12381hash
>= "0.0.3"
 bls12381signature

scaml
>= "1.5.0"

tezosbls12381polynomial
>= "0.1.3"
 tezosplompiler

tezosplonk
< "1.0.0"