Kgothatso Ngako 3b68633f59 chilldkg: CI wiring, ctime_tests coverage, declassify fixes
CI:
- ci/ci.sh: new CHILLDKG environment variable, passed to configure as
  --enable-module-chilldkg (mirroring FROST).
- .github/workflows/ci.yml: default CHILLDKG: 'no' and CHILLDKG: 'yes'
  in every job that enables FROST, except the x86_64 matrix entry that
  deliberately builds without the ecdh module (chilldkg requires
  schnorrsig + ecdh; the configure-time dependency error would fire
  there). YAML validity and per-job dependency presence checked
  programmatically.

ctime_tests:
- src/ctime_tests.c: run a full ChillDKG session (n = 2, t = 2) through
  the public API under the memory checker: hostpubkey_gen, params_hash,
  participant_step1, coordinator_step1, participant_step2,
  coordinator_finalize, participant_finalize, participant_recover and
  recovery_ack_sign. Host secret keys, session randomness, aux
  randomness and the resulting secret shares are undefined (secret);
  all protocol messages, the certificate, threshold public key, public
  shares, recovery data, ack signature and the secret-free state1
  objects are defined (public). state2 stays secret (contains the
  secret share).

Constant-time fixes found by running the new block under
MemorySanitizer (valgrind unavailable locally; MSan build via clang +
CMake). All are missing declassifications of secret-derived but public
(or public-outcome) values, following the frost module's
secp256k1_declassify pattern with justification comments; no real
constant-time bugs were found:
- hostpubkey_gen: declassify the computed host public key before
  serialization (public output).
- participant_step1: declassify the zero-randomness check result (only
  reveals "the RNG returned 32 zero bytes", which aborts the session).
- encpedpop participant_step1: declassify the pubnonce point before
  serialization (public, part of pmsg1).
- chilldkg_schnorrsig_sign: declassify the signer public key before
  normalization/parity branch, and declassify the return value (a
  failure only reveals a zero derived nonce, negligible probability).
- vss_commit: declassify the VSS commitments before serialization
  (public, part of pmsg1).
- vss_verify_secshare: declassify secshare*G before the infinity/eq
  checks (equals the public pubshare in honest runs; the discrete log
  is not revealed).
- simplpedpop_participant_investigate (proactive audit; not reached by
  ctime_tests): declassify the secshare-sum comparison result (the
  public fault code reveals it anyway).

Verified: MSan ctime_tests exits 0; autotools make check 10/10 (the
local tree is configured without --enable-ctime-tests because neither
valgrind nor an MSan-instrumented gcc build is available; CI runs
ctime_tests under valgrind as before); CMake ctest 428/428;
./tests --target=chilldkg and ./chilldkg_example pass.
2026-08-31 10:25:14 +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.
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