On Digital Cash-like Payment Systems

[Steven M. Bellovin]

In message <d4f1333a0511041709j48703e7aqe2d694b0366ccccc at mail.gmail.com>, "Trav
is H." writes:
>By my calculations, it looks like you could take a keypair n,e,d and
>some integer x and let e'=e^x and d'=d^x, and RSA would still work,
>albeit slowly.  Reminds me of blinding, to some extent, except we're
>working with key material and not plaintext/ciphertext.
>
Don't ever encrypt the same message twice that way, or you're likely to 
fall to a common modulus attack, I believe.

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb