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I like crypto. Need I say more?


17h
comment Arranging Vigenere Cipher into columns
This question should be on StackOverflow as it is about programming and algorithms, not about cryptographic theory. I'll move it.
Oct
17
comment Implementation of garbled circuits using RSA
RSA typically isn't used for Yao's method. They define what they use for enc a little lower in the document
Oct
17
comment How do you test randomness?
Can you never prove pseudorandomness or do we just not know how? Existance of one-way functions would imply existence of pseudorandom generators right? It would also imply $P\neq NP$.
Oct
17
comment Learnable with oracle query
Can you share with us where you came across that phrase. More context will be helpful.
Oct
16
comment I need to know number of encryption/decryption operations?
How many keys??
Oct
10
comment Finding all primitive polynomials of a certain degree in $\mathbb{F}_q$
Migrated. Hope you continue to use our site, though, as your needs require it.
Oct
10
comment Finding all primitive polynomials of a certain degree in $\mathbb{F}_q$
Two suggestions, first is to format your equations using MathJax which is supported on our site. Second, while there are cryptographic applications to your question, your question is inherently more about math. Maybe we should migrate it to Math.SE? Let me know if you want it migrated, and I'll do that.
Oct
9
comment Is .NET DESCryptoServiceProvider secure in this case?
@Jk_xp I think so. Make sure you are using a good mode. In particular, if you choose CBC or another non-authenticated mode, make sure you understand the implications of doing that in the context of your application. The remaining obvious risk is that your server could be hacked and the key stolen. If that is an acceptable risk to you, then you should be fine.
Oct
9
comment Is .NET DESCryptoServiceProvider secure in this case?
@Jk_xp your code, as is, is completely insecure since it uses DES. Now, let's say you changed it to AES. That would be a step up. But, since the key and IV are hard coded into the code, someone could reverse engineer your executable, and recover those values. Then they have both and can create their own messages.
Oct
9
comment Security analysis of Spritz?
From the paper you linked to "The virtues of Spritz as a hash function are more its simplicity of implementation and conservative design than its speed." Maybe the same can be said about Spritz as a stream cipher?
Oct
9
comment Security analysis of Spritz?
Keccak and SHA-256 are not ciphers. SHA-256 is a hash function. Keccak is a family of sponge functions which can be used to build hash functions (SHA-3 competition) or stream ciphers.
Oct
8
comment Does this guarantee a unique 32 bit Hash?
@sashank, One thing I noticed with your code is that since the string generation is deterministic, it always finds the same collisions. I changed it so it appends a random integer to "Hello" instead. Then you get some variation. I did this and ran the code 1000 times. That resulted in an average of around 57k iterations. If I run it more, it should get closer to the expected 65k.
Oct
7
comment Does this guarantee a unique 32 bit Hash?
@sashank that seems strange. Are you willing to share your code? I'd like to see what I get.
Oct
7
comment Need help solving message encrypted on an Enigma machine?
What have you tried?
Oct
6
comment Homomorphic encryption based on XOR
@user153465 If I had to guess, I'd guess the - votes came for the original question since it had a lot of holes. I gave it a +1 after your clarifying comments were added in.
Oct
6
comment Does this guarantee a unique 32 bit Hash?
@squeamishossifrage do you have any references on the collision resistance of djb2? If it has not been properly vetted by the cryptographic community, then I wouldn't use it in a case where we don't want collisions (that said, a work factor of $2^{16}$ isn't much, so I wouldn't use that either).
Oct
6
comment Does AES CTR mode store header information in encrypted files?
Not sure. Haven't ever really looked.
Oct
6
comment How to guarantee every plaintext is in a rainbow table?
Depends. What is the length and how big is your hard drive?
Oct
6
comment How can one recover a message from the RSA system?
crypto.stackexchange.com/questions/1614/…
Oct
6
comment How can one recover a message from the RSA system?
Brute force. Will take no time on a computer.