In the original paper introducing RSA it is implied that one should first choose d and then calulate e from p, q, and d. However, I have found in other places (such as the wikipedia article on RSA) that one should first calculate e, and only then calclulate d from it. Which of these two methods ...

Over on the bitcoin forums I asked why the bitcoin client computes SHA-256(SHA-256(x)) as its cryptographic hash for a variety of purposes. The leading theory--since the bitcoin author has disappeared--seems to be that from a security standpoint it could be sort-of analogous to upping the number ...

Considering a cryptographic hash, such as MD5 or SHA2, denoted by the function H(m) where m is an arbitrary binary string, there is a lot of material available that deals with potential weakness to preimage attack. I am interested in resistance to preimage attack where the cryptographic hash is a...

Are there any available test cases for testing elliptic curves like secp256k1 (Korblitz curves from http://www.secg.org/collateral/sec2_final.pdf)? For curves like P192 there are for example those values: http://point-at-infinity.org/ecc/nisttv . Moreover, what other ways one should test an impl...