meta user
network profile
| bio | website | redtwitz.com |
|---|---|---|
| location | Paraguay | |
| age | 28 | |
| visits | member for | 1 year, 7 months |
| seen | Apr 19 at 17:44 | |
| stats | profile views | 14 |
Mathematician. Power user. Coding enthusiast.
|
Feb 15 |
comment |
Why is triple-DES using three different keys vulnerable to a meet-in-the-middle-attack? Could you please explain where the 114 comes from? |
|
Jan 4 |
comment |
Will length-extension work if secret is not prefixed but appended to the data? No it isn't. But compared to, e.g., HMAC, it suffers from other flaws. See: Why is h(m||k) insecure? |
|
Dec 20 |
comment |
Reason(s) for using a KDF for encryption keys The output of a PBKDF2 implementation may be hexadecimal, but you can convert that output to whatever you want. Although, there are AES implementations that accept hexadecimal keys. |
|
Dec 20 |
comment |
Double Encrypting with two different keys It's important that the keys are actually independent, not just unique. To similar algorithms with related keys could go as far as canceling each other out, resulting in unencrypted plaintext. |
|
Dec 16 |
comment |
creating a small number from a cryptographically secure random string @fgrieu: That typo was a byproduct of the edit. Thanks. Which algorithm is the Best is relative. The algorithm provides randomness and is easy to implement, but it generates only 0.79 bits of output for every bit of input. (I assume that's what you mean by odds of failure.) Of course, if $x^2 \leq n$, the algorithm becomes rather inefficient. |
|
Dec 15 |
comment |
creating a small number from a cryptographically secure random string @neubert: See comment above. |
|
Dec 15 |
comment |
creating a small number from a cryptographically secure random string @Thomas: I see what you mean. I'll expand on that when I have a little more time. The division in X < (N / K) * K is integer division. If we were interested in integers below 100, we can use all X such that X < (256 / 100) * 100 = 2 * 100 = 200. With X < K, there would be no need for the modulus. |
|
Dec 15 |
comment |
creating a small number from a cryptographically secure random string @Thomas: I took this a premise, since the numbers of a random sequence should be completely independent, so it cannot matter which numbers we use (and in which order). But other than the quote each nameable subsequence of random sequence should be random as well from Infinity and the mind (hardly solid cryptography), I can't find any reference. |
|
Oct 24 |
comment |
Is it feasible to build an index of prime factors? @Hamidam: My point is that there are $2.42\cdot10^{533}$ times as many primes smaller than $2^{2048}$ than there are atoms in the observable universe. Unless we can store $2.42\cdot10^{533}$ bits of data in a single atom, it doesn't really matter what we're counting. The largest atom known to mankind is an isotope of Ununoctium that consists of 530 subatomic particles: 118 protons, 118 electrons and 294 neutrons. |
