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May
22
revised Is “non-repudiation” automatically proven, given the other three tenets of info security?
added 1271 characters in body
May
22
comment Is “non-repudiation” automatically proven, given the other three tenets of info security?
Right, but TLS allows for remote party authentication during the handshake, via certificate exchange, independently from the use of the exchanged key. Authenticating the sender as not only being the party you began the conversation with, but the party you wanted to begin the conversation with, is key to authenticating the messages exchanged as genuine. It would thus follow that the D-H scheme which I was referring to doesn't actually provide authentication, and thus it cannot provide non-rep. Perhaps that requires a change in definition of "authenticity" from my OP.
May
22
revised Is “non-repudiation” automatically proven, given the other three tenets of info security?
added 2 characters in body
May
22
comment Is “non-repudiation” automatically proven, given the other three tenets of info security?
... yes, but on its face this is no different than if I chose to trust a self-signed certificate when initiating a TLS handshake. Just because only you and I know a key and can thus communicate confidentially and with integrity, doesn't mean I actually know who you are and can thus verify that the messages I am getting are coming from whom I expect them to. I would say this does not provide authentication, because verifying a message as genuine, authenticating it, involves positive identification of the sender as the party who should be sending the message in the first place.
May
22
comment Is “non-repudiation” automatically proven, given the other three tenets of info security?
Yes, mostly. We are assuming, for the purposes of this question, that no cryptographic secrets are compromised; that is a different problem.
May
22
asked Is “non-repudiation” automatically proven, given the other three tenets of info security?
May
13
comment How does hashing work?
Well if you're using a secure hash (>=256-bit digest size) then storing the hashed value of "password" is going to increase your storage size. In addition, if an attacker were ever to see that 50% of the user accounts had the same password hash, he'd know that all he'd have to do is crack one password and he has access to 50% of the user accounts. You should be "salting" your password hashes; there are a variety of methods, but the end result is that the same password hashed by the same algorithm produces a different digest, because of an additional unique salt value for each account.
May
9
comment How do spammers verify the validity of a huge amount of email addresses?
... and in that case they don't care.
May
1
comment Is publishing your public IP address a security threat?
This. Posting your public IP on a message board might raise interest in trying to hack the computer or network behind it, but there's really no way to avoid someone else knowing about it (even if that person is the anonymous proxy gateway you route your traffic through).
Apr
30
revised The security level in hash function
deleted 1 characters in body
Apr
12
comment How is “hacking” even possible if I “defend” properly?
"As the defender, you must win 100% of the time. A hacker only needs to win once." - This, x1000.
Apr
9
revised How does hashing work?
added 250 characters in body
Apr
9
answered How does hashing work?
Apr
5
comment DDoS - Impossible to stop?
Short and sweet, but somewhat incorrect. Most DDoSs are the result of a botnet. Botnets, however massive, are a subset of the Internet, that attack by making sustained, rapid requests, often in a manner differing significantly from legitimate traffic (no legitimate user sends SYN after SYN without completing the handshake). More sophisticated attacks that turn legitimate users against a site (DNS hacking, malicious Slashdot-style linking) are harder to defend against, but also harder to pull off and control (as in Tom Leek's analogy; you set it up and hope for the worst).
Apr
5
comment DDoS - Impossible to stop?
@makerofthings - Your ISP is still trying to send all other traffic to you, and you still have to perform some cursory inspection of the packet to determine it's a rotten egg. It's a losing game; a coordinated DDoS attacker can add zombies more easily than you can reduce the time/effort needed to reject their packets.
Mar
21
revised Future proof encryption possible in theory?
added 9 characters in body
Mar
20
awarded  Citizen Patrol
Mar
11
revised Banking application login leaks information
added 1 characters in body
Mar
8
awarded  Yearling
Mar
6
answered what is the difference between a mac and a digital signiture