anvil

Anvil is a Java 25 multi-module cryptography library published under the org.exploit.anvil Maven group. The modules are split by primitive, curve, and threshold protocol layer so applications can depend only on the pieces they use.

Anvil is a continuation of tss4j under Java 25 and is part of the TKeeper Java 25 API transition. It is intended to be used in TKeeper and other exploit.org products.

Java packages currently use the existing org.exploit.* namespaces. Maven coordinates use org.exploit.anvil:{artifact}:{version}.

Coordinates

Current project version:

0.1.0

Gradle usage with the BOM:

dependencies {
    implementation platform("org.exploit.anvil:bom:0.1.0")

    implementation "org.exploit.anvil:ecc-secp256k1"
    implementation "org.exploit.anvil:paillier"
}

Gradle usage without the BOM:

dependencies {
    implementation "org.exploit.anvil:ecc-secp256k1:0.1.0"
    implementation "org.exploit.anvil:paillier:0.1.0"
}

The BOM aligns all Anvil artifacts to the same version. The modules are published as normal Java artifacts with Maven metadata; they are not shaded. Consumers receive transitive Java dependencies through their build tool, while native library resolution remains explicit at runtime.

Runtime

The build is configured for Java 25 and compiles with preview features enabled. Code that reaches native bindings uses the Java Foreign Function and Memory API. Runtime launches that use native-backed modules should enable native access for the application class path:

java --enable-native-access=ALL-UNNAMED ...

Native-backed modules load their system library first and then try bundled resources under natives/{os}-{arch}/ if present in the runtime class path.

Native library names used by the loaders:

Module	Native library
bigint	gmp
ecc-secp256k1	secp256k1
ecc-ed25519	sodium, libsodium
xchacha20-poly1305	sodium, libsodium

Loader resource tags are formed from linux, macos, or windows plus amd64 or aarch64, for example linux-amd64 or macos-aarch64.

Modules

Artifact	Module path	Main packages	Scope
bom	:bom	none	Java platform BOM for Anvil artifact alignment.
bigint	:bigint	org.exploit.bigint	GMP-backed arbitrary precision integers, CSPRNG access, prime and Blum-prime generation.
util	:util	org.exploit.anvil.util	Shared byte encoding and message digest helpers.
ecc-spi	:ecc-spi	org.exploit.ecc.spi, org.exploit.ecc.util	Curve, key, point, signer, verifier, signature, and hash-to-curve interfaces.
ecc-secp256k1	:ecc-secp256k1	org.exploit.ecc.secp256k1	secp256k1 keys, point operations, ECDSA, recoverable ECDSA, BIP340, Taproot helpers, hash-to-curve.
ecc-ed25519	:ecc-ed25519	org.exploit.ecc.ed25519	Ed25519 keys, point operations, EdDSA signing and verification.
ecc-p256	:ecc-p256	org.exploit.ecc.p256	P-256 keys, point operations, ECDSA, recoverable ECDSA, hash-to-curve.
paillier	:paillier	org.exploit.crypto.paillier	Paillier key generation, encryption/decryption, MtA helpers, and Paillier-related ZK proofs.
shamir	:shamir	org.exploit.crypto.shamir	Shamir splitting and recovery for elliptic-curve private scalars.
t-schnorr	:t-schnorr	org.exploit.tss.frost	FROST core contexts, preprocessing, partial signing, and aggregation.
frost-ed25519	:t-schnorr:frost-ed25519	org.exploit.tss.frost.ed25519	FROST Ed25519 scheme and SHA-512 cipher suite.
frost-secp256k1	:t-schnorr:frost-secp256k1	org.exploit.tss.frost.secp256k1	FROST secp256k1 schemes, including Schnorr, BIP340, and Taproot variants.
frost-p256	:t-schnorr:frost-p256	org.exploit.tss.frost.p256	FROST P-256 scheme and SHA-256 cipher suite.
t-ecdsa	:t-ecdsa	org.exploit.tss.gg20	GG20 threshold ECDSA client, contexts, MtA runners, commitments, integrity checks, and partial signature aggregation.
t-ecies	:t-ecies	org.exploit.ecies	Threshold ECIES client, ElGamal KEM, partial decrypt flow, AES-GCM and ChaCha20-Poly1305 ciphers.
xchacha20-poly1305	:xchacha20-poly1305	org.exploit.crypto.aead	XChaCha20-Poly1305 AEAD wrapper over libsodium.
zk-spi	:zk-spi	org.exploit.crypto.zk	Proof, prover, verifier, statement, and witness interfaces.
zk-dlog	:zk-dlog	org.exploit.crypto.zk.dlog	Discrete-log proof utilities: Pedersen commitments, Chaum-Pedersen, and DLEQ.

License

Apache License 2.0.