186 reputation
2
bio website
location London, United Kingdom
age 31
visits member for 2 years, 4 months
seen Dec 13 at 13:52

Sep
29
comment How do I generate a number for a lottery and later proves its existence
Sounds like you need some kind of commitment scheme. Whereby you can publish (commit to) a value (your lottery number) that you can later reveal, with the restriction that the receivers can verify that it was not changed between commitment and reveal, but are also unable to determine the original value prior to the reveal. Another example protocol is available here.
Jan
6
comment Digital Signature with Encryption
@LiorOhana - Digital signature schemes are in part intended to permit others to authenticate the message is from you, and has not been altered. If you are trying to prove to yourself that nothing has changed, there's not really any need for a digital signature at all - simply store the hash. Obviously the hash must be stored in such a way that a potential attacker cannot modify, but the same requirement holds true for the private key in a digital signature scheme, so you must already have the ability to do this.
Jan
6
answered Digital Signature with Encryption
Aug
6
awarded  Supporter
Aug
6
comment inverse of 985 mod(φ60131)
@Thomas Since this algorithm is fundamental to the operation of RSA, crypto seems like a reasonable location. I believe it was originally tagged with "homework", so I assume this is some sort of assignment to demonstrate breaking of RSA by factoring the public key.
Aug
6
answered How long does it take to extract a key from a FIPS-140 Level 2 device?
Aug
6
awarded  Teacher
Aug
6
answered inverse of 985 mod(φ60131)