Kgothatso Ngako d1c817b528 chilldkg: Phase 6 - test vectors, FROST integration, docs, example
Final phase of the ChillDKG module: upstream test vectors, a
DKG->FROST integration test, boundary tests, full module
documentation and a runnable example.

Test vectors:
- tools/test_vectors_chilldkg_generate.py converts all 10 upstream
  bip-frost-dkg JSON vector files into src/modules/chilldkg/vectors.h
  (modeled on tools/test_vectors_frost_generate.py; takes the vectors
  directory as an argument; upstream pinned to commit
  a91896883f85b159415ecf298d5e844879af112d, recorded in the generated
  header with the exact regeneration invocation; regeneration is
  reproducible byte-for-byte).
- tests_impl.h vector runners execute 191 of 241 upstream cases
  through the public API: hostpubkey_gen, params_hash,
  participant_step1/step2/finalize/investigate,
  coordinator_step1/finalize/investigate, recover. Happy paths are
  byte-exact (pmsg1/cmsg1/pmsg2/cmsg2/dkg_output/recovery/cinv);
  error cases assert both the fault enum and fault_index against
  expectedError.participantId. The 50 skipped cases are
  wrong-length/wrong-count inputs not expressible with the
  fixed-size C API; each skip is documented in vectors.h.

Boundary/robustness tests: t=1, t=n, n=2, a full n=128/t=2 session
end-to-end with per-participant secshare*G == pubshare checks and a
recovery roundtrip, and a state1 memcpy roundtrip (step2 from a copied
state object).

DKG->FROST integration test (guarded by ENABLE_MODULE_FROST): a full
ChillDKG session (n=3, t=2) feeds (secshare, thresh_pk, pubshares)
directly into the frost module. ChillDKG's thresh_pk is already
TapTweak'ed, so frost_tweak_cache_init is called with no further
tweaks (frost's tweaked x-only key asserted equal to the x-only part
of the ChillDKG thresh_pk); signers 0 and 2 run nonce_gen, nonce_agg,
session_init with the shared x = id+1 convention, frost_sign,
partial_sig_verify and partial_sig_agg; the aggregate signature
verifies as a plain BIP-340 signature against the threshold key.

Example: examples/chilldkg.c runs a full 2-of-3 DKG session (host key
generation, params hash, participant/coordinator steps, finalize, and
a recovery roundtrip via participant_recover) with fixed-size buffers
and secret erasure. Wired into Makefile.am and
examples/CMakeLists.txt exactly like frost_example (runs as a TEST);
chilldkg_example binary added to .gitignore.

Docs: src/modules/chilldkg/chilldkg.md now documents the protocol
summary, message-flow table with exact byte sizes, blame taxonomy,
recovery workflow, security notes (host key reuse/retention, fresh
randomness per session, state secrecy, recovery-data sensitivity) and
the pinned reference commit; src/modules/frost/frost.md points at the
new module as the intended DKG.

Bug fix found by the vector runner (recover tcId 9): the internal
recover() passed a possibly-NULL fault_index from coordinator_recover
to certeq_verify, which dereferences it on failure; now uses a local.

Verified: make check 10/10 (3 test suites + 7 examples incl.
chilldkg_example, exit 0 when run); CMake ctest 428/428 with chilldkg
+ frost, and a no-frost build confirms the ENABLE_MODULE_FROST guard;
make distdir includes vectors.h, the example and the generator.

The module is feature-complete against bip-frost-dkg v0.3.0-dev at
a91896883f85b159415ecf298d5e844879af112d. The BIP is still a draft;
tagged hashes and wire formats may change upstream.
2026-08-31 06:52:58 +02:00
2026-08-31 00:05:16 +02:00
2026-08-31 00:05:16 +02:00
2013-05-09 15:24:32 +02:00
2026-08-31 00:05:16 +02:00

libsecp256k1-zkp

Dependencies: None

A fork of libsecp256k1 with support for advanced and experimental features

Added features:

  • Experimental module for ECDSA adaptor signatures.
  • Experimental module for ECDSA sign-to-contract.
  • Experimental modules for Confidential Assets (Pedersen commitments, range proofs, and surjection proofs).
  • Experimental module for address whitelisting.
  • Experimental module for Schnorr signature half-aggregation.
  • Experimental module for FROST (BIP 445).

Experimental features are made available for testing and review by the community. The APIs of these features should not be considered stable.

Build steps

Obtaining and verifying

The git tag for each release (e.g. v0.6.0) is GPG-signed by one of the maintainers. For a fully verified build of this project, it is recommended to obtain this repository via git, obtain the GPG keys of the signing maintainer(s), and then verify the release tag's signature using git.

This can be done with the following steps:

  1. Obtain the GPG keys listed in SECURITY.md.
  2. If possible, cross-reference these key IDs with another source controlled by its owner (e.g. social media, personal website). This is to mitigate the unlikely case that incorrect content is being presented by this repository.
  3. Clone the repository:
    git clone https://github.com/bitcoin-core/secp256k1
    
  4. Check out the latest release tag, e.g.
    git checkout v0.7.1
    
  5. Use git to verify the GPG signature:
    % git tag -v v0.7.1 | grep -C 3 'Good signature'
    
    gpg: Signature made Mon 26 Jan 2026 07:42:46 PM UTC
    gpg:                using RSA key 2840EAABF4BC9F0FFD716AFAFBAFCC46DE2D3FE2
    gpg: Good signature from "Pieter Wuille <pieter@wuille.net>" [unknown]
    gpg:                 aka "Pieter Wuille <pieter.wuille@gmail.com>" [full]
    gpg:                 aka "[jpeg image of size 5996]" [undefined]
    gpg: WARNING: This key is not certified with a trusted signature!
    gpg:          There is no indication that the signature belongs to the owner.
    Primary key fingerprint: 133E AC17 9436 F14A 5CF1  B794 860F EB80 4E66 9320
         Subkey fingerprint: 2840 EAAB F4BC 9F0F FD71  6AFA FBAF CC46 DE2D 3FE2
    

Building with Autotools

$ ./autogen.sh       # Generate a ./configure script
$ ./configure        # Generate a build system
$ make               # Run the actual build process
$ make check         # Run the test suite
$ sudo make install  # Install the library into the system (optional)

To compile optional modules (such as Schnorr signatures), you need to run ./configure with additional flags (such as --enable-module-schnorrsig). Run ./configure --help to see the full list of available flags. For experimental modules, you will also need --enable-experimental as well as a flag for each individual module, e.g. --enable-module-rangeproof.

Building with CMake

To maintain a pristine source tree, CMake encourages to perform an out-of-source build by using a separate dedicated build tree.

Building on POSIX systems

$ cmake -B build              # Generate a build system in subdirectory "build"
$ cmake --build build         # Run the actual build process
$ ctest --test-dir build      # Run the test suite
$ sudo cmake --install build  # Install the library into the system (optional)

To compile optional modules (such as Schnorr signatures), you need to run cmake with additional flags (such as -DSECP256K1_ENABLE_MODULE_SCHNORRSIG=ON). Run cmake -B build -LH or ccmake -B build to see the full list of available flags.

Cross compiling

To alleviate issues with cross compiling, preconfigured toolchain files are available in the cmake directory. For example, to cross compile for Windows:

$ cmake -B build -DCMAKE_TOOLCHAIN_FILE=cmake/x86_64-w64-mingw32.toolchain.cmake

To cross compile for Android with NDK (using NDK's toolchain file, and assuming the ANDROID_NDK_ROOT environment variable has been set):

$ cmake -B build -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK_ROOT}/build/cmake/android.toolchain.cmake" -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=28

Building on Windows

The following example assumes Visual Studio 2022. Using clang-cl is recommended.

In "Developer Command Prompt for VS 2022":

>cmake -B build -T ClangCL
>cmake --build build --config RelWithDebInfo

Usage examples

Usage examples can be found in the examples directory. To compile them you need to configure with --enable-examples.

To compile the examples, make sure the corresponding modules are enabled.

Benchmark

If configured with --enable-benchmark (which is the default), binaries for benchmarking the libsecp256k1-zkp functions will be present in the root directory after the build.

To print the benchmark result to the command line:

$ ./bench_name

To create a CSV file for the benchmark result :

$ ./bench_name | sed '2d;s/ \{1,\}//g' > bench_name.csv

Reporting a vulnerability

See SECURITY.md

Contributing to libsecp256k1

See CONTRIBUTING.md

Description
Experimental fork of libsecp256k1 with support for pedersen commitments and range proofs.
Readme 15 MiB
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