Re: what is RSA keylength the length of?

Daniel Moore <taihaiteki@xxxxxxxxxxxxxx> writes:


People talk about "the key length" in discussions of the RSA algorithm.

In learning about it at a textbook level I know that an RSA key is a
pair of integers. (One is used as a power to exponentiate a value and
ususally labeled e or d, the other as a divisor to then divide the
result usually labeled n.)

NO. The pair of integers are two primes which are multiplied together to
give n. the exponents e and d are easily computed from those. e is usually
only about 6 bits long. d is roughly the same size as n.


So what does "the key length," as a singular reference, refer to?? For
example if I hear about a "1024-bit RSA key" what is 1024 bits long?

The product of that pair of primes.
And each of the two primes are half that length.

.

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