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Sep
27
revised What makes RSA secure by using prime numbers?
added 44 characters in body
Sep
27
comment What makes RSA secure by using prime numbers?
@poncho: Right, thanks, the implication goes the other way. Obviously, $d = 65$ satisfies $5d = 1 \pmod {\phi(133)}$.
Sep
27
revised What makes RSA secure by using prime numbers?
added 84 characters in body
Sep
27
revised What makes RSA secure by using prime numbers?
added 297 characters in body
Sep
27
revised What makes RSA secure by using prime numbers?
added 2 characters in body
Sep
27
answered What makes RSA secure by using prime numbers?
Sep
23
comment Is the inverse of a secure PRP, also a secure PRP?
@RickyDemer: Quite right, the security model outlined in that paper entails that the adversary must have no better than a 0.5 probability to predict how the last two blocks in the code book are permuted. No feistel cipher is secure in that model. Arguably, neither is AES-128, since a (hypothetical) adversary that is able to process $2^{128}-2$ blocks, is implicitly also able to mount a brute force search of the key.
Sep
22
revised Why is TLS susceptible to protocol downgrade attacks?
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Sep
21
revised Why is TLS susceptible to protocol downgrade attacks?
added 173 characters in body
Sep
21
answered Why is TLS susceptible to protocol downgrade attacks?
Sep
20
comment Is the inverse of a secure PRP, also a secure PRP?
@D.W.: AFAIK the strongest notion would be that the adversary in fact has the entire code book and is only limited by a linear function of the size of the code book. This notion might make more sense in the case of block ciphers with a 64 bit block size, but theoretically it ought to be stronger than both of the notions you mention.
Sep
18
revised Can PBKDF2 be used to create an XOR cipher key to encrypt random plaintext?
added 498 characters in body
Sep
18
revised Can PBKDF2 be used to create an XOR cipher key to encrypt random plaintext?
added 498 characters in body
Sep
18
comment Can PBKDF2 be used to create an XOR cipher key to encrypt random plaintext?
@rath: Indeed, if the PBKDF doesn't produce pseudo random output because the internal function used as the "PRF" has a flaw, the crypto would be broken even if the derived key was used for a proper symmetric cipher.
Sep
16
awarded  Tag Editor
Sep
16
revised sha-3 wiki description
added 64 characters in body
Sep
16
suggested suggested edit on sha-3 tag wiki
Sep
14
comment RSA key pair generation using PRNG with same seed
@owlstead: No problem, edit away, but perhaps you should narrow down your question, so that it becomes clear my then last paragraph is the adequate answer.
Sep
10
comment Could RDRAND (Intel) compromise entropy?
The point being raised by Dale Emmons here change.org/en-GB/petitions/… is that the hardware random bits are fetched after the other entropy has already been both collected and processed. This means that one might question the claim that the chosen string is really XORed with an unknown string.
Sep
10
comment Should new applications still use RSA? Is it worth going down the ECDH route for protocols?
Could you provide some details about which "breakthroughs" everyone is talking about? It should be noted that neither RSA nor ECC are secure for post-quantum cryptography.