Examples with IntegerPolynomial com.github.zhenwei.core.pqc.math.ntru.polynomial.IntegerPolynomial used on opensource projects

Example 1 with IntegerPolynomial

use of com.github.zhenwei.core.pqc.math.ntru.polynomial.IntegerPolynomial in project LinLong-Java by zhenwei1108.

the class NTRUEncryptionKeyPairGenerator method generateKeyPair.

/**
 * Generates a new encryption key pair.
 *
 * @return a key pair
 */
public AsymmetricCipherKeyPair generateKeyPair() {
    int N = params.N;
    int q = params.q;
    int df = params.df;
    int df1 = params.df1;
    int df2 = params.df2;
    int df3 = params.df3;
    int dg = params.dg;
    boolean fastFp = params.fastFp;
    boolean sparse = params.sparse;
    Polynomial t;
    IntegerPolynomial fq;
    IntegerPolynomial fp = null;
    // choose a random f that is invertible mod 3 and q
    while (true) {
        IntegerPolynomial f;
        // choose random t, calculate f and fp
        if (fastFp) {
            // if fastFp=true, f is always invertible mod 3
            t = params.polyType == NTRUParameters.TERNARY_POLYNOMIAL_TYPE_SIMPLE ? Util.generateRandomTernary(N, df, df, sparse, params.getRandom()) : ProductFormPolynomial.generateRandom(N, df1, df2, df3, df3, params.getRandom());
            f = t.toIntegerPolynomial();
            f.mult(3);
            f.coeffs[0] += 1;
        } else {
            t = params.polyType == NTRUParameters.TERNARY_POLYNOMIAL_TYPE_SIMPLE ? Util.generateRandomTernary(N, df, df - 1, sparse, params.getRandom()) : ProductFormPolynomial.generateRandom(N, df1, df2, df3, df3 - 1, params.getRandom());
            f = t.toIntegerPolynomial();
            fp = f.invertF3();
            if (fp == null) {
                continue;
            }
        }
        fq = f.invertFq(q);
        if (fq == null) {
            continue;
        }
        break;
    }
    // if fastFp=true, fp=1
    if (fastFp) {
        fp = new IntegerPolynomial(N);
        fp.coeffs[0] = 1;
    }
    // choose a random g that is invertible mod q
    DenseTernaryPolynomial g;
    while (true) {
        g = DenseTernaryPolynomial.generateRandom(N, dg, dg - 1, params.getRandom());
        if (g.invertFq(q) != null) {
            break;
        }
    }
    IntegerPolynomial h = g.mult(fq, q);
    h.mult3(q);
    h.ensurePositive(q);
    g.clear();
    fq.clear();
    NTRUEncryptionPrivateKeyParameters priv = new NTRUEncryptionPrivateKeyParameters(h, t, fp, params.getEncryptionParameters());
    NTRUEncryptionPublicKeyParameters pub = new NTRUEncryptionPublicKeyParameters(h, params.getEncryptionParameters());
    return new AsymmetricCipherKeyPair(pub, priv);
}

Example 2 with IntegerPolynomial

use of com.github.zhenwei.core.pqc.math.ntru.polynomial.IntegerPolynomial in project LinLong-Java by zhenwei1108.

the class NTRUEncryptionPrivateKeyParameters method init.

/**
 * Initializes <code>fp</code> from t.
 */
private void init() {
    if (params.fastFp) {
        fp = new IntegerPolynomial(params.N);
        fp.coeffs[0] = 1;
    } else {
        fp = t.toIntegerPolynomial().invertF3();
    }
}

Example 3 with IntegerPolynomial

use of com.github.zhenwei.core.pqc.math.ntru.polynomial.IntegerPolynomial in project LinLong-Java by zhenwei1108.

the class NTRUEngine method decrypt.

/**
 * @param e
 * @param priv_t  a polynomial such that if <code>fastFp=true</code>, <code>f=1+3*priv_t</code>;
 *                otherwise, <code>f=priv_t</code>
 * @param priv_fp
 * @return an IntegerPolynomial representing the output.
 */
protected IntegerPolynomial decrypt(IntegerPolynomial e, Polynomial priv_t, IntegerPolynomial priv_fp) {
    IntegerPolynomial a;
    if (params.fastFp) {
        a = priv_t.mult(e, params.q);
        a.mult(3);
        a.add(e);
    } else {
        a = priv_t.mult(e, params.q);
    }
    a.center0(params.q);
    a.mod3();
    IntegerPolynomial c = params.fastFp ? a : new DenseTernaryPolynomial(a).mult(priv_fp, 3);
    c.center0(3);
    return c;
}

Example 4 with IntegerPolynomial

use of com.github.zhenwei.core.pqc.math.ntru.polynomial.IntegerPolynomial in project LinLong-Java by zhenwei1108.

the class NTRUEngine method MGF.

/**
 * An implementation of MGF-TP-1 from P1363.1 section 8.4.1.1.
 *
 * @param seed
 * @param N
 * @param minCallsR
 * @param hashSeed  whether to hash the seed
 */
private IntegerPolynomial MGF(byte[] seed, int N, int minCallsR, boolean hashSeed) {
    Digest hashAlg = params.hashAlg;
    int hashLen = hashAlg.getDigestSize();
    byte[] buf = new byte[minCallsR * hashLen];
    byte[] Z = hashSeed ? calcHash(hashAlg, seed) : seed;
    int counter = 0;
    while (counter < minCallsR) {
        hashAlg.update(Z, 0, Z.length);
        putInt(hashAlg, counter);
        byte[] hash = calcHash(hashAlg);
        System.arraycopy(hash, 0, buf, counter * hashLen, hashLen);
        counter++;
    }
    IntegerPolynomial i = new IntegerPolynomial(N);
    while (true) {
        int cur = 0;
        for (int index = 0; index != buf.length; index++) {
            int O = (int) buf[index] & 0xFF;
            if (// 243 = 3^5
            O >= 243) {
                continue;
            }
            for (int terIdx = 0; terIdx < 4; terIdx++) {
                int rem3 = O % 3;
                i.coeffs[cur] = rem3 - 1;
                cur++;
                if (cur == N) {
                    return i;
                }
                O = (O - rem3) / 3;
            }
            i.coeffs[cur] = O - 1;
            cur++;
            if (cur == N) {
                return i;
            }
        }
        if (cur >= N) {
            return i;
        }
        hashAlg.update(Z, 0, Z.length);
        putInt(hashAlg, counter);
        byte[] hash = calcHash(hashAlg);
        buf = hash;
        counter++;
    }
}

Example 5 with IntegerPolynomial

use of com.github.zhenwei.core.pqc.math.ntru.polynomial.IntegerPolynomial in project LinLong-Java by zhenwei1108.

the class NTRUSigner method signHash.

private byte[] signHash(byte[] msgHash, NTRUSigningPrivateKeyParameters kp) {
    int r = 0;
    IntegerPolynomial s;
    IntegerPolynomial i;
    NTRUSigningPublicKeyParameters kPub = kp.getPublicKey();
    do {
        r++;
        if (r > params.signFailTolerance) {
            throw new IllegalStateException("Signing failed: too many retries (max=" + params.signFailTolerance + ")");
        }
        i = createMsgRep(msgHash, r);
        s = sign(i, kp);
    } while (!verify(i, s, kPub.h));
    byte[] rawSig = s.toBinary(params.q);
    ByteBuffer sbuf = ByteBuffer.allocate(rawSig.length + 4);
    sbuf.put(rawSig);
    sbuf.putInt(r);
    return sbuf.array();
}