I found a good resource for ECC test vectors: http://dev.experimentalstuff.com:8082/ I suspect the three most important curves to support are the NIST suite-B ones: NIST P-256 (aka secp256r1), NIST P-384 (aka secp384r1), and NIST P-521 (aka secp521r1) Do you know if libgcrypt support these curves? /Simon