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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.

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eightShirt
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  • 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. – CodesInChaos Apr 29 '16 at 06:27

1 Answers1

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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.

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otus
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