12,262 reputation
32559
bio website paul-ebermann.tumblr.com
location Berlin, Germany
age
visits member for 2 years, 9 months
seen 12 secs 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:


Jan
8
revised Why hash or salt when signing?
typo, formatting
Jan
7
comment Are there other digital certificate formats than X.509?
The title of that quote is a bit misleading ... it suggests that X.509 is a standard incorporating all other standards (or a format incorporating all other certificate formats), but actually it only says that every certificates for every use case can be expressed in X.509.
Jan
7
revised Are there other digital certificate formats than X.509?
formatting, full text in title
Jan
7
comment How is the MD2 hash function S-table constructed from Pi?
@Trina I converted your "answer", which didn't actually answer the question, into three comments on the question (as there are size limits).
Jan
4
revised Webcam random number generator
grammar/spelling
Jan
2
awarded  Nice Answer
Dec
27
awarded  Enlightened
Dec
27
awarded  Nice Answer
Dec
26
awarded  Sportsmanship
Dec
24
comment Can we ensure the security of a crypto-algorithm and -implementaton against acoustic cryptanalysis?
@CodesInChaos Is there a "standard constant time code" implementation for RSA? (I know that they exist for symmetric algorithms like AES.)
Dec
22
comment Is a Mersenne-twister cryptographically secure if I truncate the output?
Please note that Stack Exchange sites are not discussion sites, but Question-and-answer sites. Repeatedly editing a question to ask different things in reaction to answers it not really useful – better create a new follow-up question (which still should be able to stand on its own).
Dec
19
awarded  Guru
Dec
16
comment Two-timing a one-time pad
It adds weaknesses which are difficult to analyze. Don't do it. If you can exchange your OTP key securely, you likely will be able to exchange a bigger one, too. Use a different part of it for each key exchange.
Dec
16
comment Implement deniable encryption with AES/RSA
@e-sushi There were "More than 20 comments" before, I can assure you. (That post becomes auto-flagged if that happens, so we tend to see them all.)
Dec
10
comment Slow one-way pseudo-random permutation?
@RichieFrame Keccak's permutation is almost as easy to compute in the reverse direction as in the forward direction.
Dec
6
comment Why should I use Authenticated Encryption instead of just encryption?
Actually, many "confidentiality-only" modes actually even don't give good confidentiality when attacked by an active attacker (which can modify the messages or mount chosen plaintext or chosen ciphertext attacks). Therefore these modes in practice (for a communication channel) need to be used together with some MAC even to just obtain the confidentially part. An AE mode just combines these into one.
Dec
2
comment What is the function of the secret key “r” in Poly1305?
I think you missed the point of the question ... which is "why must $r$ stay secret", not "why do we have a nonce?"
Dec
1
answered Can you help me understand hash-preserving encryption?
Nov
27
comment What are the practical difference between 256-bit, 192-bit, and 128-bit AES encryption?
Actually, the MixColumns-step is applying the same operation on each column, and the different block size variants of Rijndael only differ in the number of columns, not in the size of those. So the matrix stays the same for all Rijndael (and AES) variants.
Nov
27
comment What are the practical difference between 256-bit, 192-bit, and 128-bit AES encryption?
@mikeazo Yes, I think it should be "128 bit block" there. (I'm going to edit this now.)