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| bio | website | |
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| age | ||
| visits | member for | 1 year, 4 months |
| seen | 31 mins ago | |
| stats | profile views | 31 |
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May 21 |
comment |
Is Wikipedia's table about SHA-2 collisions correct? @PaŭloEbermann: I think reduced round attacks might be mentioned in this context, if the number of rounds attacks start to move up beyond some comfort limit. Otherwise mentioning them might just obscure the fact that there are logically reduced round attacks against any algorithm with multiple rounds (because after all that's why multiple rounds were made part of the design to begin with). |
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May 21 |
comment |
Is Wikipedia's table about SHA-2 collisions correct? @PaŭloEbermann: Nit-pick, but if reduced round attacks are relevant, if found at least one against 2 round Keccak: naya.plasencia.free.fr/Maria/papers/Keccak_differential.pdf |
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May 20 |
revised |
Is Wikipedia's table about SHA-2 collisions correct? Question changed |
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May 20 |
answered | Is Wikipedia's table about SHA-2 collisions correct? |
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May 20 |
comment |
How random are commercial TRNGS I think you are probably asking the wrong question for this forum; this is not the right place to ask for product recommendations. However, theoretical cryptography can tell how to use a not necessarily completely reliable TRNG for seeding a PRNG in such way that you at least do not make matters worse. |
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May 20 |
comment |
How random are commercial TRNGS Check the documentation. How has the manufacturer ensured that the output is unbiased? By using conditioning (using what method and with which security parameters), or by tuning the hardware to ensure the raw unconditioned output does not show any statistical bias (after how many requests)? |
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May 19 |
reviewed | Approve suggested edit on One time Pad Adversary |
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May 19 |
reviewed | Reject suggested edit on What is the post-quantum cryptography alternative to Diffie-Hellman? |
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May 16 |
comment |
Is this a sensible cryptographic protocol intending to reduce the impact of compromised security? Just a hint: Generally the basic idea is that you get cryptographic security by ensuring that the key never gets anywhere it might get compromised. Your protocol might give you security by obscurity at best, given your own assumptions about the threat scenario. |
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May 16 |
comment |
Generate fixed length cipher text from arbitrary length plaintext Correct, the whole idea behind en.wikipedia.org/wiki/Numbers_station encryption is that the broadcast goes on forever, so that you don't get an indication when the actual traffic occurs. Obviously you are also theoretically correct about file encryption and drive encryption, but in practice there is equally obviously always a practical upper bound on how large a file might get, before you have to change medium. |
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May 16 |
revised |
Generate fixed length cipher text from arbitrary length plaintext added 348 characters in body |
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May 16 |
comment |
Generate fixed length cipher text from arbitrary length plaintext You hide the amount of actual plain text content. For instance, compare it to the WWII continuous broadcasts of seemingly random words. If you were listening in and didn't know which keyword to listen for, you couldn't tell when a message began or ended. |
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May 16 |
answered | Generate fixed length cipher text from arbitrary length plaintext |
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May 15 |
reviewed | Approve suggested edit on Partial collisions for md5 |
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May 14 |
reviewed | Approve suggested edit on Why is H(k||x) not a secure MAC construction? |
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May 14 |
comment |
Why is the following RSA PRNG cryptographically secure? If you mean algorithm 5.35 in HAC, you will only output the least significant bit of each intermediary $x_i$ value. |
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May 14 |
comment |
Is there a way to do fair exchange between two parties who don't trust each other? @RickyDemer: Done right, yes. OTOH did I implement a bignum library that is approximately 100 times faster for similar 8192 bit integer operations, than another existing bignum library, on the same machine. Either way it boils down to how you define "much". |
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May 13 |
comment |
Is there a way to do fair exchange between two parties who don't trust each other? @RickyDemer: That's basically the same thing as using contemporary key stretching techniques for deriving a 128 bit key from a 32 bit key, so I guess you could have answered yes. :) |
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May 13 |
comment |
Is there a way to do fair exchange between two parties who don't trust each other? @RickyDemer: Do you mean use e.g. 32 bit encryption, and swap keys before the other party has a chance to decrypt the message by brute force? I guess there are Internet Poker protocols based on such primitives. |
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May 13 |
comment |
Is there a way to do fair exchange between two parties who don't trust each other? @RickyDemer: Without additional assumptions and constraints, protocols with the latter property are not possible without a third party. cs.utexas.edu/~shmat/courses/cs395t_fall04/pagnia.pdf |
