155 reputation
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bio website mrclay.org
location United States
age
visits member for 1 year, 2 months
seen 7 hours ago

Developer for etc. (UF College of Education); core contributor to the Elgg social network framework; co-creator and maintainer of Minify; blogger since 2001.

Am typically busy pouring work into open source projects.

Profiles: GitHub, Google Code, @mrclay_org


Jul
13
comment What is the purpose of update() in popular hash APIs?
I think the most likely explanation for the API is to support intermediate hashes ("I need separate hashes for i1, i1 + i2, and i1 + i2 + i3"): docs.oracle.com/javase/1.4.2/docs/guide/security/…
Jul
13
comment What is the purpose of update() in popular hash APIs?
Yep. hashlib uses update() in their HMAC implementation: hg.python.org/cpython/file/default/Lib/hmac.py
Jul
13
accepted What is the purpose of update() in popular hash APIs?
Jul
13
comment What is the purpose of update() in popular hash APIs?
@CodesInChaos The alternative would be to accept the entire input in digest(). There's nothing about the design of hash algorithms that requires feeding the input in piece by piece. This seems to run against the en.wikipedia.org/wiki/Single_responsibility_principle
Jul
12
asked What is the purpose of update() in popular hash APIs?
Jun
13
comment Algorithm: How to use x and y mouse movement co-ordinates to generate random data?
You'll want to have a look at random.js from the Stanford JS Crypto Library. E.g., this function is registered to handle mouse movements. Appears to be based on Fortuna
Jun
10
comment Prepend information about encryption implementation to the stored data
Perhaps a better question would have been: Are there existing standards for this metadata?
Jun
10
comment Is it possible to anonymize web traffic so that the IP Address cannot be determined while still being able to determine distinct IPs?
The space of IPv4 is so small that I don't see how any deterministic scheme could be secure. I think the assumption that the attacker will have compromised the key is unreasonable.
Jun
10
comment When using HMAC, does key encoding matter?
From this answer follows the question: Wouldn't it be wise to truncate any key down to size B rather than let HMAC hash it down to L?
Jun
10
comment When using HMAC, does key encoding matter?
I find this argument just as compelling. Thanks!
Jun
10
comment When using HMAC, does key encoding matter?
From @fgrieu's answer I see I was naively conflating block length (B) with output size (L) of the hash. So now I see a key of length B could theoretically provide more entropy than the hashed key (length L) resulting from the encoding operation.
Jun
10
awarded  Scholar
Jun
10
accepted When using HMAC, does key encoding matter?
Jun
10
awarded  Student
Jun
10
awarded  Supporter
Jun
9
asked When using HMAC, does key encoding matter?