13,486 reputation
33171
bio website paul-ebermann.tumblr.com
location Berlin, Germany
age
visits member for 3 years, 3 months
seen 3 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:


May
4
answered Block cipher encryption of decryption with the same key
May
2
comment From Factorisation of semiprimes to breaching confidentiality
Please add some details to your question: What cryptosystem are you using?
May
2
revised From Factorisation of semiprimes to breaching confidentiality
formatting.
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
29
awarded  Nice Answer
Apr
27
awarded  Necromancer
Apr
22
asked What are the key differences between the draft SHA-3 standard and the Keccak submission?
Apr
21
reviewed Approve suggested edit on Which algorithms are used to factorize large integers?
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.)
Apr
18
comment Existence of a map $\phi:\mathbb{Z}_{N^2}^* \mapsto \mathbb{F} $
Every function between finite subsets of $\mathbb R$ can be represented by a polynomial (just use the Lagrange interpolation polynomial). I would guess this transfers to maps from $\mathbb Z_{N^2}^*$ to $\mathbb F$, even though that polynomial might not be the simplest possible one.
Apr
18
comment How can I convert numbers into prime numbers?
Welcome to Cryptography Stack Exchange. From your answer, it seems like you have some more needs which are not clearly stated in the question. Maybe you could expand your question a bit?
Apr
18
comment Using Stream Cipher as CSPRNG
@StephenTouset The "outputs won't repeat" distinguisher is not universal for stream ciphers, I think, just for counter mode block ciphers or similar stuff. E.g. if you use a stream cipher build from a PRF in CTR mode, it will repeat just as often as expected for a true random stream.
Apr
16
comment The relationship between the key length and encrypt time in Xor algorithm?
Could you elaborate a bit what your "encryption algorithm using the XOR method" is exactly? For an one-time pad, the key length should be as much as the message length, so I suppose you are using something with repeated key?
Apr
9
awarded  Revival
Apr
2
awarded  Popular Question
Mar
30
comment Why the need to hash before signing small data?
Hmm, while this corrects some mistakes in the question, it doesn't really answer the underlying question: Would ECDSA be safe for small messages if we omitted the hashing step?
Mar
30
revised Is it possible to weaken a bitcoin private key by “using” it elsewhere?
deleted 373 characters in body
Mar
26
comment How useful is NIST's Randomness Beacon for cryptographic use?
Actually, an insider potentially could know these strings even longer ahead, assuming a predictable internal source.
Mar
23
comment Questions about hash functions
It looks like this would contradict the meaning of "secure hash", but I'm not sure how to formally prove it from the usual hash properties (collision/preimage/second preimage resistance)