On Tue, 2004-03-23 at 10:22, Rich Salz wrote:
> RSA works on input that has the same number of bits as the RSA key size.
> (An earlier message from you disagreed with this; you're wrong.)
>
> In other words, a 1024-bit RSA key works on 1024 bits of input and
> returns 1024 bits of output. If your input is not the same size as the
> key, you must use padding to make it so. If you do not use padding,
> than the RSA algorithm cannot be executed.
I think that this issue ought to be cast more precisely. First, what do
we mean when we talk about a 1,024-bit input? Does this mean an input in
which bit number 1023 (starting from 0, on the right) is set to 1? If
that is the case, then the standard, PKCS #1-based padding mechanisms do
not operate on 1,024-bit inputs, for such mechanisms always make sure
that the numerical value of the input string is smaller than that of the
modulus, by setting to zero at least the most significant byte of the
input string.
Therefore, what is a 1,024-bit input?
______________________________________________________________________
OpenSSL Project http://www.openssl.org
Development Mailing List [EMAIL PROTECTED]
Automated List Manager [EMAIL PROTECTED]
