jt wrote: > Looking up into Crypto.PublicKey.RSA, I see there is a computed value > named "u" for which I can't see the use. The value of "u" is the > inverse of p modulo q, in the code: > obj.u = pubkey.inverse(obj.p, obj.q) > Can someone tell me where this value could be used in the RSA scheme? > (it is not used in the code anyway)
Yes, it is. Look in _fastmath.c. It's used in rsaDecrypt: /* fast path */ /* m1 = c ^ (d mod (p-1)) mod p */ /* m2 = c ^ (d mod (q-1)) mod q */ /* h = u * ( m2 - m1 ) mod q */ <-- right here /* m = m2 + h * p */ > > Thx, > -- > jt -- http://mail.python.org/mailman/listinfo/python-list