}

	return encrypt(pub, em)
}

// ErrDecryption represents a failure to decrypt a message.
// It is deliberately vague to avoid adaptive attacks.
var ErrDecryption = errors.New("crypto/rsa: decryption error")

// ErrVerification represents a failure to verify a signature.
// It is deliberately vague to avoid adaptive attacks.
var ErrVerification = errors.New("crypto/rsa: verification error")

and rem = u - quo·v.


Long Division

Division in a computer proceeds the same as long division in elementary school,
but computers are not as good as schoolchildren at following vague directions,
so we have to be much more precise about the actual steps and what can happen.

We work from most to least significant digit of the quotient, doing:

 • Guess a digit q, the number of v to subtract from the current