3,865 reputation
1621
bio website
location United States
age
visits member for 3 years, 2 months
seen 7 hours ago

Oct
24
revised How are salt values more secure?
improved grammar
Oct
24
comment Operation which needs much computing power to be created, but just a little to be solved?
The "just a little to be solved" part is easy: declare that 0 is always a solution. $\;$
Oct
23
comment Operation which needs much computing power to be created, but just a little to be solved?
@StephenTouset : $\:$ How? $\;\;\;\;$
Oct
23
comment Format Preserving Encryption for 32 or 64 bit plaintext values
I would recommend using HMAC, since it is presumably a secure PRF. $\:$ I have no idea what the impact on performance would be. $\;\;\;\;$
Oct
22
answered Format Preserving Encryption for 32 or 64 bit plaintext values
Oct
20
comment Can we run a probabilistic function on ciphertext with Functional Encryption (or Attribute Based Encryption)?
@TravisMayberry : $\:$ That depends on what the PRF takes as input. $\;\;\;\;$
Oct
20
comment Can we run a probabilistic function on ciphertext with Functional Encryption (or Attribute Based Encryption)?
@JianLiu : $\;\;\;$ If $sk_f$ can be quantum, then it might be possible "to prevent Bob from providing the same randomness to $\hspace{.04 in}f$" every time. $\:$ There are non-deterministic PRNGs, but that would just move the problem to preventing "Bob from providing the same" entropy to the PRNG every time. $\:$ Do invoker-randomizable PRFs count as "non-deterministic"? $\;\;\;\;\;\;\;$
Oct
19
comment Can we run a probabilistic function on ciphertext with Functional Encryption (or Attribute Based Encryption)?
You could instead "contain within $f$ a" PRF, so that Bob can only provide "the same randomness to $f$" on each call with the same input.
Oct
19
revised Can we run a probabilistic function on ciphertext with Functional Encryption (or Attribute Based Encryption)?
improved grammar
Oct
18
revised Why can't garbled circuits be reused?
fixed title's grammar
Oct
17
comment Existential Unforgeability of signature scheme against Adaptive Chosen Message Attack
No; I'm just making sure you're aware that EUF-CMA is not the strongest notion. $\;$
Oct
17
comment Existential Unforgeability of signature scheme against Adaptive Chosen Message Attack
(Also: Have you seen "the concept of" Strong "Unforgeability of signature" schemes "against Adaptive Chosen Message Attack"?) $\;$
Oct
17
comment Existential Unforgeability of signature scheme against Adaptive Chosen Message Attack
csee.wvu.edu/~xinl/library/papers/comp/goldwasser1988.pdf $\;$
Oct
16
comment Cryptography system that limits the length of the encypted message
That only affects how easy/hard it will be to do format-preserving encryption $\hspace{1.74 in}$ on the space of 160-character strings. $\;$
Oct
16
comment Cryptography system that limits the length of the encypted message
Does the list of allowed characters have an even number of elements? $\;$
Oct
15
comment Encrypted read-only message queue
You should not be encrypting "with the private key". $\:$ See this question and this answer. $\;\;\;\;$
Oct
15
comment Is there any existing cipher capable of scaling from a 1 bit key up to a one-time-pad?
Three other regions along that continuum are honey encryption, entropically-secure encryption, and encryption that remains information-theoretically secure against key-dependent messages.
Oct
10
comment How does MD5 process text which is shorter than 512 bits
en.wikipedia.org/wiki/MD5#Algorithm $\;$
Oct
8
comment How do I generate a number for a lottery and later proves its existence
@tylo : $\:$ I mean a collision with short inputs. $\;\;\;\;$
Oct
7
comment How do I generate a number for a lottery and later proves its existence
@tylo : $\:$ One uses a short collision in the actual hash function. $\;\;\;\;$