Timeline for Can I use HMAC-SHA1 in counter mode to make a stream cipher?
Current License: CC BY-SA 3.0
16 events
| when toggle format | what | by | license | comment | |
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| Jan 16, 2014 at 14:30 | comment | added | xxxxxxxxx | Please read question crypto.stackexchange.com/questions/879/… too and specifically this blog post which also talks about this subject: blog.cryptographyengineering.com/2011/09/… | |
| Jan 16, 2014 at 7:54 | vote | accept | xxxxxxxxx | ||
| Jan 15, 2014 at 9:00 | answer | added | Dmitry Khovratovich | timeline score: 12 | |
| Jan 15, 2014 at 6:18 | answer | added | ir01 | timeline score: 4 | |
| Jan 12, 2014 at 5:13 | comment | added | archie | The answers to crypto.stackexchange.com/questions/1656/… answer this question, although the question isn't phrased as well as this one. | |
| Jan 9, 2014 at 18:48 | comment | added | xxxxxxxxx | @Reid That clarifies everything. :-) Thanks very much. | |
| Jan 9, 2014 at 17:15 | comment | added | Reid | @izaera: The compression function in that proof is the compression function of the underlying iterated hash scheme (SHA1). You can see one iteration of the compression function in the first diagram on this page. | |
| Jan 9, 2014 at 15:49 | comment | added | xxxxxxxxx | @CodesInChaos: Maybe you would like to post your comment as the solution to the question so I can mark it as valid and give you credit? | |
| Jan 9, 2014 at 15:48 | comment | added | xxxxxxxxx | Thanks :-). I was mixing concepts: I thought the compression function in HMAC was the underlying digest (in this case SHA-1) which doesn't seem to be the case. | |
| Jan 9, 2014 at 15:40 | comment | added | CodesInChaos | A PRF is a keyed primitive, a hash isn't. So the terminology doesn't apply directly. But pretty much all symmetric crypto relies on belief. | |
| Jan 9, 2014 at 15:31 | comment | added | xxxxxxxxx | @CodesInChaos: BTW, is SHA-1 a PRF? If so, why? Are all crypto hashes PRFs by definition or is it something that must be proved one by one? Or is it simply that crypto hashes are "believed" to be PRFs? | |
| Jan 9, 2014 at 14:30 | history | tweeted | twitter.com/#!/StackCrypto/status/421287813620199424 | ||
| Jan 9, 2014 at 13:56 | comment | added | xxxxxxxxx | Thanks for the pointer. In wikipedia there's a pointer to a paper which proves that HMAC is a PRF under the sole assumption that the compression function is a PRF (see cseweb.ucsd.edu/~mihir/papers/hmac-new.html). | |
| Jan 9, 2014 at 13:26 | comment | added | CodesInChaos | Yes, CTR mode works with any PRF. HMAC-SHA1 is a decent PRF. | |
| Jan 9, 2014 at 13:08 | review | First posts | |||
| Jan 9, 2014 at 13:25 | |||||
| Jan 9, 2014 at 12:49 | history | asked | xxxxxxxxx | CC BY-SA 3.0 |