Reputation
2,383
Top tag
Next privilege 2,500 Rep.
Create tag synonyms
Badges
8 25
Newest
 Talkative
Impact
~39k people reached

14h
comment How to calculate plaintext from modpower cipher
Right, there might be some other, faster algorithm than factoring the modulus. I'm not sure I understand what you mean about the discrete log problem for composite moduli.
2d
comment Can we do modulus switching for number theoretic encryption?
In theory I guess you could, but what would be the purpose of it?
Apr
27
comment Security of tokenization of plain text conversations - cryptanalysis
For example, imagine encrypting a sixteen-character english word with AES-ECB. Each character can be encoded in one byte, so this is one block of AES ciphertext. However, you can encode the ciphertext to be stored in only about nine characters of Chinese, which gives you extra space to store metadata and headers with the ciphertext for easy parsing/decryption.
Apr
27
comment Security of tokenization of plain text conversations - cryptanalysis
Marketing gimmick is part of it, but having worked on a system like this I can say authoritatively that there is a real reason why Chinese is advantageous: SaaS websites usually count a Chinese character as a single 'character' for field length limitations, but the entire Chinese code page lets you encode about 14-15 bits of cipertext into one character of Chinese. Using Chinese allows you to make ciphertexts as short as possible relative to the way 'length' is measured by these websites.
Apr
26
comment What functional encryption scheme can be used to compute a linear function?
iacr.org/archive/eurocrypt2008/49650145/49650145.pdf
Apr
26
comment What functional encryption scheme can be used to compute a linear function?
By 'inner-product encryption' I mean an encryption which supports inner product computation on ciphertexts.
Apr
26
comment What functional encryption scheme can be used to compute a linear function?
Can your linear function be represented as a matrix? If so, you might be able to get away with something simpler like inner-product encryption to multiply your matrix (i.e. evaluate your linear function) on a value (vector) in the message space.
Apr
25
revised Searchable Encryption with Substring Search
Change title to be less generic
Apr
25
comment Searchable Encryption with Substring Search
I don't understand what exactly you want. The second paper you linked by Chase and Shen is pretty much the state of the art in this area, so you might want to just do that.
Apr
25
comment Searchable Encryption with Substring Search
CryptDB doesn't do this, and its security is not well-understood. CryptDB is not the right tool for this problem.
Apr
24
comment How to solve this public-key cryptography system?
It would be helpful if you could retype the problem instead of just including a picture of it.
Apr
24
revised How to solve this public-key cryptography system?
added tag
Apr
23
comment What is transaction capacity of a POS using 3DES DUKPT?
Maybe you should explain the acronyms here and give some context for your question? I can't make heads or tails of what you're asking.
Apr
19
comment Which are similar encryption techniques as honey encryption?
Ristenpart published a follow-up at this year's Eurocrypt; you can check the proceedings.
Apr
19
revised Is there a theorem to determine the elliptic curve parameters based on the group order?
deleted 1 character in body
Apr
18
comment Differences between OWP and OWF and their IND-CPA security
Can't you use the G-L hardcore bit to get a much simpler PRG than the one from the HILL result?
Apr
13
comment Find collision in Ajtai's hash function using short vector
I concur. I wish all questions were this nicely-written.
Apr
7
comment Can you give me a summary of cryptographic hardness assumptions?
If you email Vercauteren he might be able to get the site back up...
Apr
7
comment Can you give me a summary of cryptographic hardness assumptions?
web.archive.org/web/20120121090326/http://www.ecrypt.eu.org/… ?
Apr
3
comment Non-iterative cryptographic hash functions
Also, would (e.g.) a sponge-based hash like Keccak qualify as non-iterative?