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Jan
4
accepted How does ECDH arrive on a shared secret?
Jan
4
comment How does ECDH arrive on a shared secret?
To avoid continuing the back and forth in Comments, I created a Chat Room and have posted a few more questions there.
Jan
4
comment How does ECDH arrive on a shared secret?
I see... ok, just to again make sure I understand.. and thanks to @StephenTouset's nugget of wisdom (thanks Stephen!). When Alice is dotting $g$ to itself $a$ times, Alice isn't really doing the "dot" operation $a$ times, but is somehow using a magical math formula that gets Alice $A$ much quicker than actually doing the "dot" $a$ times. So the final $S$ from Alice's perspective is $g$ dot $g$ $b$ times to get $B$ (supplied by Bob), then $B$ dot $B$ $a$ times. And from Bob's: $A$ dot $A$ $b$ times. Which ends up at the same point in the curve... the shared secret.
Jan
4
comment How does ECDH arrive on a shared secret?
Let me just confirm I understand you...Everyone knows the starting point ($g$), everyone knows where Alice ended up ($A$), everyone knows where Bob ended up ($B$), and everyone knows the actual elliptic curve. But only Alice knows how many iterations of "dot" she did ($a$), and only Bob knows how many iterations he did ($b$). And once they know each other's $A$ and $B$, they then continue the other's "dot" operation. AKA, Alice takes $g$ and $B$ and "dots" it $a$ more times, and Bob takes $g$ and $A$ and "dots" it $b$ more times, and they both land at $S$, the shared secret... is that it?
Jan
4
revised How does ECDH arrive on a shared secret?
added two <BR> tags for formatting
Jan
4
asked How does ECDH arrive on a shared secret?
Dec
8
awarded  Commentator
Dec
8
comment What is the functional role of CKY-I and CKY-R in ISAKMP (IKEv1)?
@e-sushi thanks for the edits, looks much better now.
Dec
8
comment What is the functional role of CKY-I and CKY-R in ISAKMP (IKEv1)?
Awesome, thanks for your answer Poncho! That clears that up for me!
Dec
8
accepted What is the functional role of CKY-I and CKY-R in ISAKMP (IKEv1)?
Dec
5
asked What is the functional role of CKY-I and CKY-R in ISAKMP (IKEv1)?
Dec
2
comment SHA1 - SSL/TLS Cipher Suite
There is also some good information about this in this question: crypto.stackexchange.com/questions/19286/…
Sep
25
awarded  Supporter
Sep
25
accepted SHA1 no longer considered secure for SSL Certificates — what about Cipher Suites?
Sep
25
comment SHA1 no longer considered secure for SSL Certificates — what about Cipher Suites?
Ahh yea. This morning I woke up thinking about this question and I realized I had the order wrong with TLS/SSL, I was studying IPsec and I had the orders confused between the two. Either way, I think you're answer (@dave_thompson_085) and @otus 's edit clarified things for me. Thanks for your help!
Sep
24
comment SHA1 no longer considered secure for SSL Certificates — what about Cipher Suites?
Interesting. Let me make sure I understand. SHA1/MD5 to sign SSL Certificates is not secure because an attacker knows the starting text (is Plaintext still the appropriate term?) that generated a particular digest. Whereas with SSL/TLS (3.0+), since the starting text is encrypted HTTP data, it isn't known and therefore finding a collision against the HMAC Digest in the packet is much, much more difficult? If that is the case, since SSL/TLS does Encryption and then HMAC'ing, isn't the "starting text" simply the cipher text in the application data record, and therefore already known?
Sep
24
comment SHA1 no longer considered secure for SSL Certificates — what about Cipher Suites?
To be honest, I don't think I had ever realized. I updated my post to include the correct usage "imminently", rather than immanent. Thanks for the heads up, hobbs.
Sep
24
revised SHA1 no longer considered secure for SSL Certificates — what about Cipher Suites?
Fixed grammar, thanks Hobbs!
Sep
23
asked SHA1 no longer considered secure for SSL Certificates — what about Cipher Suites?
Apr
3
revised TLS Key Block calculation - What is a PRF?
Edited title to better reflect the right answer to make it easier for others to search for the same content.