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I'm an aspiring cryptographer. Other interests include software engineering and Linux-based system administration.

I can be contacted at: reid [at] rwiggins [dot] net.


Mar
17
revised What prevents a padding standard to cause a data loss?
Fix spelling of 'standard'
Mar
12
comment How does the key size per data bit influence the security?
It will take $2^{127}$ tries on average, not $2^{64}$. If the probability of each guess being correct is $1/2^n$, it takes $2^n / 2 = 2^{n-1}$ guesses to have a 50% chance of success.
Mar
9
comment Using a hash with a constant key to create easily verifiable codes
Well, I have two problems with this answer: (1) it doesn't mention HMAC, which the question just screams to recommend IMO, and (2) it suggests signing a digest of the message, which should already be handled by the signature's padding scheme.
Mar
9
comment Finding an x such that xP = (11,44) on an elliptic curve
Some folks write curve points with uppercase letters.
Mar
5
comment Any use for now-defunct Mt Gox Yubikey?
48 bits is not a whole lot. I don't know much about the system is setup, but could you possibly brute-force that?
Mar
5
revised Is it possible to calculate the 'skeleton key' for DUAL_EC_DRBG? What would it take?
Fix typo
Mar
5
answered Is it possible to calculate the 'skeleton key' for DUAL_EC_DRBG? What would it take?
Mar
4
revised Is it possible to calculate the 'skeleton key' for DUAL_EC_DRBG? What would it take?
Fixed typo in title
Feb
19
answered Necessity of changing $p$ and $q$ when your private key is exposed?
Feb
15
comment The difference between these 4 breaking Cipher techniques?
Hmm, (re)reading this answer, perhaps it would be prudent to reorder these from weakest to strongest, so that each attack builds on the previous one. (That is the typical presentation.) I think this answer might serve in the future as a useful high-level reference for the different attack types. I've noticed that the associated Wikipedia article(s) are of particularly poor quality in that department.
Feb
10
answered Is the random data at the end of my decrypted message supposed to be there?
Feb
4
comment What exactly is the base for the KECCAK (SHA3) claim that a security strength of 256 bits is “post-quantum sufficient”?
@figlesquidge: See this paper by Bernstein, particularly the third page. In it, he argues that the BHT quantum algorithm for collision-finding will cost more than Grover's. All thanks goes to nightcracker, who provided me this citation about a month ago.
Feb
3
comment Can passwords be stored securely so that a similarity comparison can be made?
That's essentially the only (secure) way, as far as I can see. Suppose you had some password storage algorithm that allowed you to compute a "similarity metric" between two digests (or one digest and one input; the scenario doesn't change). Then couldn't one use the similarity metric to optimize a brute-force search? (That is: follow a path that maximizes the similarity metric.) This isn't a proof, but it does intuitively explain the problem here.
Feb
3
comment Can passwords be stored securely so that a similarity comparison can be made?
Well: if the password change form asks for your previous password, it can use it to check similarity between the new password and the old (after checking it against the stored digest in the DB for security, of course).
Feb
2
answered DES-encrypted cipher
Feb
2
comment The difference between these 4 breaking Cipher techniques?
What particular difficulties are you having understanding the above? In what way(s) are you confused?
Jan
30
comment How do institutions like banks do RSA with big primes?
As an aside, banks probably don't use numbers much larger than most organizations, or even people. They're more cautious about things like key management, but exceptionally strong crypto is widely available these days; it's more of a matter of ensuring your protocols are properly secure instead of picking a insanely high (computational) security level.
Jan
30
awarded  Talkative
Jan
28
comment One-way function and uninvertible function
Can you update the question with your definition of one-way and uninvertible? To prove the statement you're given, you need to understand the essence of why the two definitions are different.
Jan
20
comment Is SHA-256 safe when used in this way?
Minor nit: "where the attacker tries to figure out information about the original message from the hash" is not a preimage attack necessarily. A preimage attack is, given some $f(x)$, try to find an $x'$ such that $f(x) = f(x')$. Even if $f(x)$ exposes some information about $x$, it may not necessarily lead to a preimage attack. This is related to the notion of a hard-core predicate.