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seen Oct 17 at 2:11

Hi!

If you're in the Pittsburgh area and are interested in security I run a user group called Steel City Hackers. Feel free to check it out @ http://www.meetup.com/Steel-City-Hackers/

Jon


Nov
3
comment Why does WPA-PSK not use Diffie-Hellman key exchange?
@Stubabe Agreed. If you aren't using 802.11w, deauths are a piece of cake. That being said, I've never actually seen a corporation use 802.11w.
Jul
16
comment Is it possible to generate a 6-digit number using 256-bit encryption?
This does not address the question.
Jul
2
comment How much stronger is RSA-2048 compared to RSA-1024?
@pg1989 If you do find the chart, I'd be very interested to see that.
Jul
2
comment Windows 8/Server 2012: Passes FIPS-140-2 despite failing AES-GCM for IV != 96 bits long?
These types of answers are why I come to stackexchange. Thanks.
Jun
5
comment Why crypto hash functions must be collision resistant and how to find resistant?
Though I agree that there is no such thing as collision-free regarding hash functions, I would disagree that hash algorithms are still constrained to fixed length outputs. Check these out for more details.
May
10
comment Finding hash almost-collisions
I know some people from CMU who do things like this all the time. I'll try to get ahold of them and see how they approached this.
May
10
comment Does knowledge of original file size provide a cryptographic weakness?
See Kerckhoff's principle; although I understand that not all cryptosystems are implemented this way, I believe that most use this as a basis.
May
10
comment Does knowledge of original file size provide a cryptographic weakness?
Just wanted to comment that a great example of this is ARP.
May
8
comment Many consecutive hashes to slow down brute force attack?
PBKDF2 should do what you're looking for.
Mar
21
comment BCrypt vs Key Stretching MD5
Best table ever. I just came across this a couple weeks ago when discussing the evernote breach and have since presented it to upper management. Also, there was a great talk on these types of hashing algorithms via Security Now #388.
Jan
7
comment Why does WPA-PSK not use Diffie-Hellman key exchange?
@hakoja It is worth noting that the PMK is not only derived from the password "using PBKDF," but actually comes from function PBKDF2(Passphrase, SSID, ssidlen, 4096, 256) where Passphrase is the shared key, SSID is the ESSID name, ssidlen is the length of the ESSID, 4096 is the number of times the information is hashed via SHA1, and 256 is the output key length. The PMK for ESSID "Linksys" is not the same as the PMK for ESSID "Cisco" even if the Nonces, MACs, and passphrases would be exactly the same.
Jan
7
comment Why does WPA-PSK not use Diffie-Hellman key exchange?
@CodesInChaos I would like to clarify your comment a bit since it seems to be worded in a way that can be easily misconstrued. All users who share a WPA/WPA2 PSK WiFi network can not read each other's traffic unless they have the 4-way handshake from the beginning of the other client's session. The PTK is derived from the PMK but also adds entropy via the SNonce, ANonce, and MAC addresses of both sides which is exchanged in the 4-way handshake. The only thing that all clients on a WPA/WPA2 PSK wifi network can decrypt are Multi/Broadcast packets (See: GMK/GTK).
Dec
19
comment AES key length greater than 256 bits - is it dangerous to do an implementation outside of the standard?
Yeah, I gotcha. I just wanted to make sure it was clear because "sufficiently strong" seems to be an understatement. In my opinion, if you were concerned with brute-force attacks (To the tune of >256 bit AES not being enough), and you are concerned with quantum computing throwing a brick at typical prime-based discrete encryption, I would move to something like lattice-based crypto. cims.nyu.edu/~regev/papers/pqc.pdf I am unable to answer your question directly, which is why I left a comment and didn't author an answer.
Dec
19
comment AES key length greater than 256 bits - is it dangerous to do an implementation outside of the standard?
There have been previous questions which show just how incredibly unnecessary a >256-bit key is for AES. In summary, the way it was explained to me was that our sun doesn't even have enough energy in an entire a year to get us close to cracking 256-bit encryption. It's a physics restriction in addition to the computationally expensive restriction.