1,134 reputation
313
bio website xagawa.net
location
age
visits member for 2 years
seen 1 hour ago

20h
answered Key construction in the Full Cramer-Shoup cryptosystem
2d
comment Key construction in the Full Cramer-Shoup cryptosystem
Could we change the scheme? If so, there is a chance.
Apr
21
awarded  Yearling
Apr
17
comment Is the strength of RSA over quadratic or other cyclotomic fields as strong as over the integers?
Note: Scheidler-Williams (DCC 1995) and Takagi-Naito (IEICE Trans. J81-A1, 19980in Japanese) may be relaed to this question and discuss security.
Apr
14
revised does re-encrypting the same value with multiple keys reduce security
corrected spelling (cyphertext -> ciphertext) and improve formatting.
Apr
14
revised Homomorphic Encryption and Semantic Security using Lattices?
Correct a minor mistake and add an explanation.
Apr
14
revised PRP, PRF and modular arithmetic
Corrected minor typo.
Apr
13
answered Given a message and signature, find a public key that makes the signature valid (ECDSA)
Apr
10
awarded  Custodian
Apr
10
reviewed Approve suggested edit on Is there an algorithm to check if an elliptic curve is secure?
Apr
10
comment An example of Knapsack Cryptosystem cracks/attacks?
Try M = ...; M.LLL(); or M.BKZ()
Apr
9
comment Locally Dedcodable Codes and Private Information Retrieval
What is your question? PIR should hide an index in the query, while LDC needs not. There's a (little) gap.
Apr
4
comment Security proof of FO(Fujisaki-Okamoto) hybrid encryption
No. It is contained in the list $\mathcal{Y}$ with $c_2^*$.
Apr
3
comment Security proof of FO(Fujisaki-Okamoto) hybrid encryption
Hint: Inv stands for inversion. Check the meaning of $c_1^*$ and the claim on Pr[1].
Mar
27
answered Security proof of FO(Fujisaki-Okamoto) hybrid encryption
Mar
24
comment Is a random oracle controled by the challenger?
What do you mean by "control"? Do you mean programmability that allows a challenger to program the table of the hash function? Or, observability?
Mar
16
comment What functions allow for practical indistinguishability obfuscation?
Note: The simplest one is a class that allows us to compute a normal form of a circuit efficiently. The class of log size circuits seems ok for iO without any assumptions.
Mar
1
awarded  Enthusiast
Feb
26
awarded  Informed
Feb
26
comment PRP, PRF and modular arithmetic
Correctly speaking, the size of domain $2^{\ell}$ should be small, because the construction is based on $2^{\ell}$-DBDHI assumption.