13,083 reputation
32865
bio website paul-ebermann.tumblr.com
location Berlin, Germany
age
visits member for 3 years, 1 month
seen 18 hours ago

Don't fear to edit my posts: even if I have more reputation than you, I do make mistakes.

I'm now also a Moderator Pro Tempore (= until the first elections) at Cryptography Stack Exchange: feel free to come around and ask some cryptography questions.


My personal name is spoken as /ˈpawlo/ (IPA), in English this would be written similar to Powlo, I think (i.e. the vowels are ow and o), with an accent on the before-last syllable (which is the first in this case). It's the Esperanto form of my given name.

The photo shows my shadow, taken at night. My camera sometimes seems to forget all the other frequencies and only stores the green ones.

My current main private programming project is the game of fencing, an online abstract turn based strategy game. Implemented as a Java applet, using git as a version control system.


Some more links:


2d
comment A patched SHA1 attempt for password verification
Collision resistance is not what you should worry about for password hashes, preimage resistance is the point.
Jul
27
comment CSPRNG that cannot be used as random extractor
I guess for a PRNG you usually have a short input and longer output, while in a randomness extractor it is the other way around. That might be the key point of difference.
Jul
27
comment True Random Number Generator by milliseconds per keystroke (TRNG-Kms)
@xorcoder Please refrain from insulting other members of this site (or anyone at all). I don't see anything wrong with owlstead's answer. I deleted your comments.
Jul
14
comment Leak-proof protocol: is such a thing possible?
How would using scrypt in any way reduce the leakage rate? I can see it reducing the encryption rate, but this would not really help.
Jul
8
comment What exactly does a key do?
@Wad: yes, one of the 26 keys (the "shifting by 0" one) would be a weak key, which doesn't change anything. If you are encrypting only a single letter, then this is just a valid key as all other ones.
Jul
1
comment Attacks on AES-128 (ECB) based on some knowledge of plaintext
What are your security goals with your protocol?
Jun
29
comment Associative standard cryptographic hash function
Are restrictions on $a$ and $b$ allowed (like a fixed size or such)?
Jun
24
comment How come Shamir Secret Sharing uses Lagrange interpolation?
What does "computational complexity" mean here? These are the same polynomials, just written differently.
Jun
23
comment What algorithm would give the shortest ciphertext for very short plaintexts?
@tylo counter mode by itself doesn't provide any authentication, so an intercepting attacker who guesses the right plaintext can substitute an arbitrary different one.
Jun
18
comment Is HMAC needed for a SHA-3 based MAC?
There are MAC schemes based on SHA-3 which don't do the nested hashing of HMAC, but please don't call them "HMAC".
Jun
12
comment which of these is more secure (bcrypt vs srp)
Your answer explains why HTTPS is to be considered not secure enough, though it doesn't answer the question at all, which is whether SRP or a double bcrypt is better.
Jun
9
comment Familiar key signing over video call
@Jonhoo thanks for the note, I fixed them.
Jun
9
comment Are those RSA keys flawed?
Just to emphasize: Don't use these specific keys for anything now. If the private key was published, anyone could try it and break your cipher/signature.
Jun
1
comment How can I make a message into a blocks for NTRU?
I suppose the responses to How can I use asymmetric encryption, such as RSA, to encrypt an arbitrary length of plaintext? apply here just as well.
May
12
comment Does the secret key used in AES have to prime?
Please note that RSA doesn't use prime keys, but (usually) semi-prime ones (which are a product of two primes).
May
10
comment How to decrypt a text which is ciphered same length key?
Welcome to Cryptography Stack Exchange. Your question is missing some details – which encrytion algorithm is in use? If it is some misused one-time-pad, look other questions with that tag.
May
2
comment From Factorisation of semiprimes to breaching confidentiality
Please add some details to your question: What cryptosystem are you using?
May
2
comment Generating the keys for the RSA cryptosystem in probabilistic polynomial time
Basically, there are a lot of primes available to choose from.
May
1
comment Can XEX or XTS modes be used with only one tweak?
It would also be quite slower than original XEX, because you need two encryptions for each block, instead of one per block + one per sector.
Apr
18
comment Existence of a map $\phi:\mathbb{Z}_{N^2}^* \mapsto \mathbb{F} $
@curious Please use the edit button to include your additional requirements into the question. (And it would also be useful adding some context how this relates to cryptography, for now this looks like generic math.)