[sci.crypt] Question about choosing E & D in RSA encryption

mlm@nl.cs.cmu.edu (Michael Mauldin) (07/13/87)

Does choosing E to be a power of 2 work for RSA encryption?

If E = 2**k, then exp(M,E) mod N is just k squarings of M (mod N).

This could reduce the number of multiplications necessary for encryption
by an average of 33%  (the decryption would still take as long, since
Dalmost certainly not be a power of 2).

Does this weaken the algorithm in any way?  Has someone already suggested this?

Michael L. Mauldin (Fuzzy)		Department of Computer Science
ARPA: Michael.Mauldin@NL.CS.CMU.EDU	Carnegie-Mellon University
Phone: (412) 268-3065			Pittsburgh, PA  15213-3890