13,781 reputation
33472
bio website paul-ebermann.tumblr.com
location Berlin, Germany
age
visits member for 3 years, 8 months
seen 16 mins 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:


Nov
23
comment How can I create a fixed length output in my hash function?
We had a conversation in chat to help to understand the answers.
Nov
23
comment Advanced Access Content System (AACS) and Subset Difference techniques for Broadcast Encryption
Welcome to Cryptography Stack Exchange. We actually prefer answers which contain the information itself, not only a web link. Could you add a summary of the information to the answer? Otherwise we will convert your answer to a comment.
Nov
23
revised How can I create a fixed length output in my hash function?
add a paragraph to show how this limits the output size
Nov
23
comment Using a Non-Random IV with modes other than CBC
To say it shorter: A mode is affected if the IV touches the plaintext before encryption (and after decryption), and not directly affected (but needs the uniqueness) if IV and plaintext are separated by encryption.
Nov
23
revised How can I create a fixed length output in my hash function?
formatting to use numbered lists
Nov
23
revised How can I create a fixed length output in my hash function?
add some more details about the compression function
Nov
23
reviewed Approve copy-protection tag wiki excerpt
Nov
23
comment How can I create a fixed length output in my hash function?
@Joesavage1 The "filler content" is the appending of 9 and 0 in step 1).
Nov
23
comment How can I create a fixed length output in my hash function?
Feel free to come to our general Cryptography chat room, I'm almost always there when I'm online at all, and it is not too full.
Nov
23
comment How can I create a fixed length output in my hash function?
Just a note: In this very simple hash function's output, we (after the first input byte) always have $c = b \oplus 94h$, which means that more information is lost than necessary. Also, $b$, after an even number of bytes, is just the XOR of the even-numbered input bytes. After an odd number, it is the XOR of the odd-numbered input bytes (and 55).
Nov
23
comment Security of simple xor and s-box cipher?
@Polynomial: I added some (small-font) explanation for the notation to my article. Though in general, if you don't even know this basic mathematical notation, you are nowhere near the knowledge level necessary to design a secure cipher, sorry.
Nov
23
revised Security of simple xor and s-box cipher?
add explanations of notation
Nov
23
answered How can I create a fixed length output in my hash function?
Nov
23
revised How can I create a fixed length output in my hash function?
formatting, spelling/grammar, better title
Nov
23
comment How can I create a fixed length output in my hash function?
Welcome to Cryptography Stack Exchange! Please register your account here, to be able to comment and accept an answer.
Nov
23
revised Security of simple xor and s-box cipher?
make the notation clearer
Nov
23
comment Security of simple xor and s-box cipher?
$\mathbb{Z}_m$ is simply the set of integer numbers from $1$ to $m$. In your case, this is the same $m$ as the block size, since after each 256 blocks the effect of the block number $n$ to the cipher is the same as before. I'll try to reword it, though.
Nov
23
answered Security of simple xor and s-box cipher?
Nov
23
answered Does knowing common prefixes help crack blowfish?
Nov
23
comment Security of simple xor and s-box cipher?
You shouldn't call it "block cipher" if it doesn't work like a block cipher.