405 reputation
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location Wellington, New Zealand
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visits member for 3 years, 2 months
seen 2 hours ago

I am an undergraduate computer science and mathematics student in New Zealand. My fields of interest are computer graphics, in particular the physics of light transport, and to some extent cryptography, as well as programming and software development in general.


Dec
13
comment Why don't people hash and salt usernames before storing them
Welcome, 21840c1a3e3db69e01445c8782a99f9b.
Dec
13
comment Is it possible to decrypt symmetric key encryption without the key?
The plaintext must not be assumed to be secret - at least parts of it are probably known to the attacker (common headers, etc...). There are also real life protocols which allow an attacker to obtain unlimited amounts of plaintext/ciphertext pairs, if your encryption scheme yields the key under those circumstances it has failed.
Dec
9
comment How difficult to crack keepass master password?
Moore's Law is starting to fail already - thermal limits have been reached for semiconductor transistors and the future is all about parallelization, which scales linearly, not exponentially.
Dec
1
comment How effectively can ISPs detect illegal file sharing?
@Rob Ignorance, mostly. Most people don't know about encryption, or think it doesn't help them, or mistakenly believe it slows down their downloads (it doesn't). There's been some progress in educating users but it hasn't reached out much so far, so I really do not believe most torrent clients are set to use encryption. I could, of course, be wrong.
Dec
1
awarded  Editor
Dec
1
revised How effectively can ISPs detect illegal file sharing?
added 328 characters in body
Dec
1
answered How effectively can ISPs detect illegal file sharing?
Nov
19
comment How is the available entropy in /dev/random calculated (or estimated)?
@everyone remember this was an answer posted from crypto.SE with a different perspective on the problem. Though I have to agree it doesn't really address the question which is really about how the kernel comes up with this entropy estimate.
Nov
6
comment Can I encrypt a file incrementally?
@D.W. There are also hash tree approaches to allow MAC verification of individual packets to arbitrary granularity, but I'm not sure how practical they actually are, you still to receive most of the tree before you can begin checking and the overhead can be considerable.
Oct
31
comment How can I encrypt a file with .NET and have the same file size of the original file?
Yes, with the edit it's now clearer.
Oct
31
comment How can I encrypt a file with .NET and have the same file size of the original file?
Keep in mind the IV must sometimes be unpredictable in addition to being unique.
Oct
25
awarded  Critic
Oct
23
comment Why do we lock our computers?
@TC1 or a post-it next to the keyboard..
Oct
10
comment Will this work? Revealing identity (facebook) of person who clicks specially crafted link
The reason this link works is because you have cookies on your computer telling Facebook which account you want. The proxy website will not have these cookies and Facebook will not know what to give it, thereby returning a login page.
Oct
8
comment How to protect encryption key while application is using it
You can always delete the keyfile once your application has read the key in, and rewrite it before your application closes, if that's possible. It'll still be somewhere on the flash drive but much harder to find. But in general, if the user can read the system's RAM, all hope is lost. This belongs on IT Security, btw.
Oct
7
comment Why do most hashing functions produce hashes that have characters a-f 0-9?
Hash functions output a string of bits. The way you display them textually doesn't change their nature, only their encoding.
Oct
3
comment Why would a virus writer bother to check to see if a machine is infected before infecting it?
The user might also get a physical notice from his ISP about unreasonable email activity, which would be a suicide move for the virus.
Sep
24
comment Computational Feasibility of finding 'Good Links' of the following format
@Polynomial The server could also still accept your requests, but automatically return "no image" regardless of what you passed it, making your probability of success effectively zero, with no way for you of knowing (not very useful in this situation but can be a very powerful deterrent in some situations, in particular people trying to guess passwords)
Sep
11
comment How to check if someone is in my computer
Real hackers don't use the network to remote-control your computer, they use a butterfly with very accurately timed wing flaps, creating small changes in atmospheric pressure, which in turn causes electromagnetic radiation to hit your computer, flipping specific bits in memory thereby allowing them to alter your system's state to their advantage.
Sep
10
comment Encryption and compression of Data
@lynks It is not, however, a definitive test of randomness. If the encrypted file does not compress, your cipher isn't a complete joke, but may still very well be insecure in the extreme. If the encrypted file does compress, all hope is lost and you may as well hand over the plaintext to the bad guys.