ECIES lives in feature-ecies.
It uses an ElGamal-style KEM over the key curve plus an AEAD payload cipher.
Encryption uses the public key, so it does not need peer participation in either quorum mode.
In mono mode, decrypt is local. TKeeper reads the active private key material, applies the optional tweak, unwraps the KEM secret, and decrypts the payload.
In threshold mode, decrypt needs a quorum. Each peer returns a partial decrypt with a DLEQ proof. The coordinator verifies each proof against the ciphertext point, the peer public share, and the partial decrypt before combining the plaintext.
In threshold mode the private key is never reconstructed.
Build with it:
./gradlew shadowJar -Pkeeper.features=ecies
Required permissions:
tkeeper.key.{keyId}.encrypt
tkeeper.key.{keyId}.decrypt
Encrypt:
POST /v1/keeper/ecies/encrypt
Body:
{
"keyId": "ecies-key",
"algorithm": "AES_GCM",
"plaintext64": "aGVsbG8=",
"tweak": "optional"
}
Response:
{
"ciphertext64": "...",
"generation": 1
}
Decrypt:
POST /v1/keeper/ecies/decrypt
Body:
{
"keyId": "ecies-key",
"algorithm": "AES_GCM",
"generation": 1,
"ciphertext64": "...",
"tweak": "optional",
"approvals": {
"keeperId": 1,
"nonce": "unique-nonce",
"timestamp": 1760000000000,
"proofs": []
}
}
Response:
{
"plaintext64": "aGVsbG8=",
"imposters": []
}
Algorithms:
AES_GCM
CHACHA20_POLY1305
Supported curves:
SECP256K1
P256
Decrypt requests can carry four eye approvals. The approval hash binds the decrypt request fields, including key id, algorithm, ciphertext, generation, tweak, nonce, and timestamp.
imposters contains peers that returned invalid partial decrypt proofs. It is only meaningful in threshold mode. Mono decrypt returns an empty list.
If quorum is still honest, threshold decrypt can succeed and report the bad peers.
Frequent Problems
ECIES endpoints are missing
Rebuild with feature-ecies.
INVALID_CIPHERTEXT
The ciphertext is malformed, from another key, or from another tweak/generation.
NOT_ENOUGH_HONEST_CLIENTS
Too many peers were unavailable or returned invalid partial decrypt proofs.