3,913 reputation
1628
bio website
location Wellington, New Zealand
age
visits member for 2 years, 10 months
seen 14 mins ago

I am an undergraduate computer science and mathematics student in New Zealand. My fields of interest are computer graphics, in particular the physics of light transport, and to some extent cryptography, as well as programming and software development in general.


Oct
9
comment Breaking RSA moduli
You will have to define "break" and "RSA moduli" - do you mean "factor" and do "RSA moduli" need to resist factorization, or do you mean any semiprime?
Oct
8
awarded  Nice Answer
Oct
6
comment Is there a string that's hash is equal to itself?
@fgrieu Indeed :) but it's pretty clear which answers I was referring to. +1'd your answer
Oct
6
comment Is there a string that's hash is equal to itself?
Please note both answers below are either misleading or do not quite follow. I do not have time to write an answer now, but someone else surely will. In the meantime, feel free to look at these couple of near-duplicates: crypto.stackexchange.com/questions/9910/…, crypto.stackexchange.com/questions/971/… (they don't contain an answer to your question, but provide good insights into how to answer this kind of question). Also, keyword "fixed point".
Oct
1
comment Small Encryption Exponent
@fgrieu If this is indeed the expected resolution path, it will be somewhat difficult to produce a solution before the deadline at this point :-)
Oct
1
comment Small Encryption Exponent
To elaborate a bit on poncho's comment, most real world RSA encryption schemes use small encryption exponents for performance, usually 3, 17 or 65537 - so $e = 7$ may not be of any help!
Sep
30
awarded  Explainer
Sep
24
awarded  Autobiographer
Sep
21
comment How much would it cost in U.S. dollars to brute force a 256 bit key in a year?
@AwalGarg Bruce can do it by simply guessing the key on the first try.
Sep
3
comment AES-ECB as an authentication mechanism
What is "Y" here? The ciphertext?
Aug
28
comment Is there a hash function which has no collisions?
@supercat and David you may want to create a chat room to discuss this (long comment chains like these tend to get automatically deleted after a bit)
Aug
9
awarded  Nice Answer
Aug
4
comment Theoretical attack on RSA
@Entimon If $p$ and $q$ are known to be close to one another, then, yes, it is fast (just like Fermat's algorithm), but if $p$ and $q$ are chosen properly (or even randomly, for sufficiently large $p$ and $q$) then $\lvert p - q \rvert$ is on the same order as $\sqrt{N}$, and in the same realm: infeasible.
Aug
1
revised Theoretical attack on RSA
fixed typo
Aug
1
revised Theoretical attack on RSA
added some notes and a bunch of links
Aug
1
answered Theoretical attack on RSA
Jul
26
comment Reversing DJB2 Hashes
Hint: I can tell you that the number I'm thinking of is even (0 modulo 2), that's not going to help you know if I'm thinking of 2, 4, or 34857188414. That information is lost when you reduce your input modulo 2^32, only the remainder remains, the original value is lost (yes, forever).
Jul
24
comment Low Public Exponent Attack for RSA
@CGFoX If you had only two congruences then your $n'$ would be on the order of $n^2$ (product of two moduli) and so your $m^3$ would be larger than $n^2$ (by an order of $n$) and you couldn't easily take the cube root without knowing the factorization of the moduli, so it doesn't work.
Jul
23
comment Which algorithm do you recommend for practical use to generate unique passwords for each website?
"If you go this route you are putting all your eggs in one basket. If you forget the master password, you lose all the derived ones. If someone guesses it, they can derive all the others." How is this any different than a password manager exactly? Or do you mean one of those online ones? And, yes, the master password must have quite a lot of entropy if you do this, at least 60 to 80 bits.
Jul
23
comment Which algorithm do you recommend for practical use to generate unique passwords for each website?
You should also consider password compromise (not the master secret, but individual passwords that you need to change for whatever reason). You could append a counter, or some other information that can be easily remembered and updated infrequently, if you don't want to store them, which I imagine is the whole point of the idea.