Tink (Java)

Facts and the checks behind them

Nothing below is copied from documentation. The check content/libraries/verify/tink/run.sh ran Tink (Java) 1.24.0 in the container image maven:3.9.16-eclipse-temurin-25 on October 20, 2026; the page must match what it printed, and each fact lists those lines.

• ECDSA signature encoding

  der

  ECDSA_P256 signatures are DER after the output prefix.

  Recorded by the check

  fact ecdsa-signature-encoding = der

• Signature prefix

  tink-5-byte

  Default templates prepend a 5-byte prefix — 0x01 and the key id — which the JDK rejected with Invalid encoding for signature.

  Recorded by the check

  fact output-prefix = tink-5-byte
  evidence output-prefix: ECDSA_P256 signature starts with 0x01 followed by the 4-byte key id, then the DER signature
  evidence output-prefix: ECDSA_P256_IEEE_P1363 signature: 69 bytes (5-byte prefix + 64)
  evidence output-prefix: ECDSA_P256 signature given to the JDK with the prefix: SignatureException: Invalid encoding for signature

• Encoding of the RAW template

  ieee-p1363

  ECDSA_P256_RAW produced 64 bytes of IEEE P1363 r‖s (no prefix, not DER); it verified with SHA256withECDSAinP1363Format.

  Recorded by the check

  fact raw-template-encoding = ieee-p1363
  evidence raw-template-encoding: ECDSA_P256_RAW signature: 64 bytes, parses as DER: false
  evidence raw-template-encoding: ECDSA_P256_RAW signature verifies in the JDK's SHA256withECDSAinP1363Format: true

• Signature encoding after PEM import

  der

  A public key imported from PEM through SignaturePemKeysetReader verified DER signatures only; a raw r‖s signature failed until re-encoded as DER.

  Recorded by the check

  fact pem-import-encoding = der

• ECDSA nonce

  random

  Random nonce: two signatures of the same message differ.

  Recorded by the check

  fact ecdsa-nonce = random

• Low-S when signing

  either

  s is not normalized: high-S values appeared among 64 signatures.

  Recorded by the check

  fact ecdsa-low-s-sign = either

• High-S when verifying

  accepts-high-s

  A signature with s replaced by n − s verified.

  Recorded by the check

  fact ecdsa-low-s-verify = accepts-high-s

• What the signing call hashes

  hashes-message

  Primitives sign the message; there is no API for signing a digest.

  Recorded by the check

  fact ecdsa-prehash = hashes-message

• Malformed ECDSA signature

  throws

  A malformed signature raises GeneralSecurityException: invalid signature.

  Recorded by the check

  fact ecdsa-malformed-signature = throws
  evidence ecdsa-malformed-signature: GeneralSecurityException: invalid signature

• ECDSA curves

  P-256P-384P-521

  P-256, P-384 and P-521 templates signed and verified.

  Recorded by the check

  fact ecdsa-curves = P-256, P-384, P-521

• EdDSA

  Ed25519

  Ed25519 templates, with and without the output prefix.

  Recorded by the check

  fact eddsa = Ed25519

• Post-quantum algorithms

  none

  No ML-DSA or SLH-DSA templates are registered in Tink for Java 1.24.0.

  Recorded by the check

  fact pqc = none
  evidence pqc: ML_DSA_65: GeneralSecurityException: Name ML_DSA_65 does not exist
  evidence pqc: SLH_DSA_SHA2_128S: GeneralSecurityException: Name SLH_DSA_SHA2_128S does not exist

• Public key formats

  spki-pem

  SPKI PEM through SignaturePemKeysetReader; otherwise keys live in Tink keysets.

  Recorded by the check

  fact public-key-formats = spki-pem
  evidence public-key-formats: SPKI PEM through SignaturePemKeysetReader, then verifying the RAW template's raw signature: GeneralSecurityException: invalid signature
  evidence public-key-formats: the same signature re-encoded as DER against the PEM-imported key: ok
  evidence public-key-formats: Tink JSON public keyset round trip: ok

• Keyset format

  tink-jsontink-binary

  Keysets serialize as Tink JSON or binary protobuf; the public keyset round-tripped through JSON.

  Recorded by the check

  fact keyset-format = tink-json, tink-binary

Usage

import com.google.crypto.tink.KeyTemplates;
import com.google.crypto.tink.KeysetHandle;
import com.google.crypto.tink.PublicKeySign;
import com.google.crypto.tink.PublicKeyVerify;
import com.google.crypto.tink.RegistryConfiguration;
import com.google.crypto.tink.signature.SignatureConfig;
import java.nio.charset.StandardCharsets;

public class Usage {
    public static void main(String[] args) throws Exception {
        SignatureConfig.register();
        byte[] message = "order #1042 approved".getBytes(StandardCharsets.UTF_8);

        // Default templates prepend a 5-byte key-id prefix that no other library expects.
        KeysetHandle tinkOnly = KeysetHandle.generateNew(KeyTemplates.get("ECDSA_P256"));
        byte[] prefixed = tinkOnly.getPrimitive(RegistryConfiguration.get(), PublicKeySign.class).sign(message);

        // For signatures other systems verify, pick a *_WITHOUT_PREFIX / *_RAW template.
        KeysetHandle portable = KeysetHandle.generateNew(KeyTemplates.get("ECDSA_P256_IEEE_P1363_WITHOUT_PREFIX"));
        byte[] raw = portable.getPrimitive(RegistryConfiguration.get(), PublicKeySign.class).sign(message);
        portable.getPublicKeysetHandle().getPrimitive(RegistryConfiguration.get(), PublicKeyVerify.class).verify(raw, message);

        System.out.println("prefixed first byte: 0x0" + prefixed[0] + ", portable signature: " + raw.length + " bytes, verified");
    }
}