我不知道我是否正确使用了此代码-> main。它非常慢。是DDS算法。它是 DSA 的实现：http ://en.wikipedia.org/wiki/Digital_Signature_Algorithm
这个循环需要很多时间
do {
pTemp = new BigInteger(l, primeCenterie, rand);
pTemp2 = pTemp.subtract(BigInteger.ONE);
pTemp = pTemp.subtract(pTemp2.remainder(q));
System.out.println("1 " + i++);
} while (!pTemp.isProbablePrime(primeCenterie)
|| pTemp.bitLength() != l);
我添加了一些 printlns，甚至它们都很慢。
import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Key {
int primeCenterie = 20;
BigInteger q;
BigInteger p;
BigInteger g;
BigInteger y;
BigInteger x;
BigInteger k;
Random rand = new Random();
Key() {
}
public void generateKey() {
q = new BigInteger(160, primeCenterie, rand);
p = generateP(q, 512);
g = generateG(p, q);
do {
x = new BigInteger(q.bitCount(), rand);
} while (x.compareTo(BigInteger.ZERO) != 1 && x.compareTo(q) != -1);
y = g.modPow(x, p);
}
private BigInteger generateP(BigInteger q, int l) {
if (l % 64 != 0) {
throw new IllegalArgumentException("L value is wrong");
}
BigInteger pTemp;
BigInteger pTemp2;
int i = 0;
do {
pTemp = new BigInteger(l, primeCenterie, rand);
pTemp2 = pTemp.subtract(BigInteger.ONE);
pTemp = pTemp.subtract(pTemp2.remainder(q));
System.out.println("1 " + i++);
} while (!pTemp.isProbablePrime(primeCenterie)
|| pTemp.bitLength() != l);
return pTemp;
}
private BigInteger generateG(BigInteger p, BigInteger q) {
BigInteger aux = p.subtract(BigInteger.ONE);
BigInteger pow = aux.divide(q);
BigInteger gTemp;
int i = 0;
do {
gTemp = new BigInteger(aux.bitLength(), rand);
System.out.println("2 " + i++);
} while (gTemp.compareTo(aux) != -1
&& gTemp.compareTo(BigInteger.ONE) != 1);
return gTemp.modPow(pow, p);
}
public BigInteger generateK(BigInteger q) {
BigInteger tempK;
int i = 0;
do {
tempK = new BigInteger(q.bitLength(), rand);
System.out.println("3 " + i++);
} while (tempK.compareTo(q) != -1
&& tempK.compareTo(BigInteger.ZERO) != 1);
return tempK;
}
public BigInteger generateR() {
k = generateK(q);
BigInteger r = g.modPow(k, p).mod(q);
return r;
}
public BigInteger generateS(BigInteger r, byte[] data) {
MessageDigest md;
BigInteger s = BigInteger.ONE;
try {
md = MessageDigest.getInstance("SHA-1");
md.update(data);
BigInteger hash = new BigInteger(md.digest());
s = (k.modInverse(q).multiply(hash.add(x.multiply(r)))).mod(q);
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(DSA.class.getName()).log(Level.SEVERE, null, ex);
}
return s;
}
boolean verify(byte[] data, BigInteger r, BigInteger s) {
if (r.compareTo(BigInteger.ZERO) <= 0 || r.compareTo(q) >= 0) {
return false;
}
if (s.compareTo(BigInteger.ZERO) <= 0 || s.compareTo(q) >= 0) {
return false;
}
MessageDigest md;
BigInteger v = BigInteger.ZERO;
try {
md = MessageDigest.getInstance("SHA-1");
md.update(data);
BigInteger hash = new BigInteger(md.digest());
BigInteger w = s.modInverse(q);
BigInteger u1 = hash.multiply(w).mod(q);
BigInteger u2 = r.multiply(w).mod(q);
v = ((g.modPow(u1, p).multiply(y.modPow(u2, p))).mod(p)).mod(q);
} catch (NoSuchAlgorithmException ex) {
Logger.getLogger(DSA.class.getName()).log(Level.SEVERE, null, ex);
}
return v.compareTo(r) == 0;
}
public static void main(String[] args) {
Key key = new Key();
key.generateKey();
byte[] data = "a".getBytes();
BigInteger r = key.generateR();
BigInteger s = key.generateS(r, data);
System.out.println(key.verify(data,r,s));
}
}