3
$\begingroup$

I'm new to cryptography and I have a doubt: I read some pages a bit different definition for the RSA private key:

In 1 - (n, d)

In 2 - (d)

In 3 - (n, p, q)

Should I consider all these answers as correct? I know that if you have d and the public key, you have n (and e), and I know pq = n too.

$\endgroup$
  • $\begingroup$ Personally I wouldn't call $d$ the private key, because it can't decrypt on its own. I'd just refer to it as the private exponent. $\endgroup$ – CodesInChaos Apr 29 '16 at 6:27
3
$\begingroup$

For private key operations you need at least $n$ (the modulus) and $d$ (the private exponent). The primes $p$ and $q$ let you calculate those – or use some shortcuts for quicker computation – so they also suffice.

In practice RSA keys often include all of those values, to avoid having to compute them as needed and to allow for optimized and unoptimized implementations.

In 2 - (d)

This would not be enough on its own, but the page actually says that the private key includes the modulus.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.