Esempio n. 1
0
 // (public) this^e % m, 0 <= e < 2^32
 public BigInteger modPowInt(int e, BigInteger m)
 {
     BigInteger r = new BigInteger();
     if (e < 256 || m.isEven())
     {
         Classic z = new Classic(m);
         r = this.exp(e, z);
     }
     else
     {
         Montgomery z = new Montgomery(m);
         r = this.exp(e, z);
     }
     return r;
 }
Esempio n. 2
0
 // (protected) this^e, e < 2^32, doing sqr and mul with "r" (HAC 14.79)
 public BigInteger exp(int e, Classic z)
 {
     if (e > 0x7fffffff || e < 1)
     {
         return ONE;
     }
     BigInteger r = new BigInteger(), r2 = new BigInteger();
     BigInteger g = z.convert(this);
     int i = nbits(e) - 1;
     g.copyTo(r);
     while (--i >= 0)
     {
         z.sqrTo(r, r2);
         if ((e & (1 << i)) > 0)
         {
             z.mulTo(r2, g, r);
         }
         else
         {
             BigInteger t = r;
             r = r2;
             r2 = t;
         }
     }
     return z.revert(r);
 }