Bouncy castle NTRU generation

Question

I've faced the next problem: I don't know where to get a byte array of private key for calling correct NTRUSigningPrivateKeyParameters.

Here is my code:

    byte [] b = new byte[16];
    Security.addProvider(new BouncyCastleProvider());

    NTRUSigningKeyGenerationParameters ntruSigningKeyGenerationParameters = NTRUSigningKeyGenerationParameters.TEST157;
    NTRUSigningPrivateKeyParameters ntruSigningPrivateKeyParameters = null;
    NTRUSigner ntruSigner = new NTRUSigner(ntruSigningKeyGenerationParameters.getSigningParameters());

    try {
        ntruSigningPrivateKeyParameters = new NTRUSigningPrivateKeyParameters(b, ntruSigningKeyGenerationParameters); // here I need to get byte array from private key
    } catch (IOException e) {
        e.printStackTrace();
    }

    ntruSigner.init(true, ntruSigningPrivateKeyParameters);
    byte [] res = ntruSigner.generateSignature(); 

Does anyone had the same problem?

Answer 1

Have your tried NTRUSigningKeyPairGenerator, and calling getEncoded() on the retrieved private key?

NTRUSigningKeyPairGenerator ntruSigningKeyPairGenerator = new NTRUSigningKeyPairGenerator();
NTRUSigningKeyGenerationParameters ntruSigningKeyGenerationParameters = NTRUSigningKeyGenerationParameters.TEST157;
ntruSigningKeyPairGenerator.init(ntruSigningKeyGenerationParameters);
AsymmetricCipherKeyPair asymmetricCipherKeyPair = ntruSigningKeyPairGenerator.generateKeyPair();
NTRUSigningPrivateKeyParameters params = (NTRUSigningPrivateKeyParameters) asymmetricCipherKeyPair.getPrivate();
System.out.println(Hex.encodeHexString(params.getEncoded()));