The cipher tag has no wiki summary.
130
votes
8answers
52k views
Why not use larger cipher keys?
RSA Security commonly uses keys of sizes 1024-bit, 2048-bit or even 3072-bit. And most Symmetric algorithms only between 112-bit and 256-bit. I do realize that the current keys are secure enough for ...
15
votes
1answer
550 views
TLS: RC4 or not RC4?
I was reading another interesting article by Matthew Green today, saying that
if you're using RC4 as your primary ciphersuite in SSL/TLS, now would be a great time to stop
As far as I'm aware ...
7
votes
1answer
466 views
Is AES-GCM recommended for SSL?
I'm looking at turning on site-wide SSL for a website I manage, and I'm wondering what the best practices for SSL configuration. I'm not too worried about compatibility with old browsers and more ...
5
votes
1answer
465 views
IIS 6.0 - mitigating BEAST
Recently, my PCI assessor informed me that my servers are vulnerable to BEAST and failed me. I did my homework and I want to change our webservers to prefer RC4 ciphers over CBC. I followed every ...
4
votes
1answer
122 views
Known plaintext; What cipher is being used here? [closed]
plaintext: CANDY VERY CRANBERRY
ciphertext: TXOtWjYhVk 8&O$4AmSA
plaintext: http
ciphertext: cZf.
plaintext: http
ciphertext: r5Hz
This is definitely somehow decodable from ...
4
votes
1answer
524 views
What are the differences between the arcfour, arcfour128 and arcfour256 ciphers in OpenSSH?
What are the differences between the arcfour, arcfour128 and arcfour256 ciphers in OpenSSH?
I am interested about: speed and security implications.
I know that arcfour is fast for file transfers, ...
4
votes
2answers
280 views
Block cipher Implementation in C++
I'm writing an implementation of a block cipher in C++. I would like to study differential cryptanalysis of the cipher, so I'm generating random plaintexts and keys and then encrypt them.
Which is ...
4
votes
2answers
231 views
Picking cipher suites for HTTPS
I'm trying to work out the best approach to choosing which cipher suites to provide, and what the issues might be.
It's my understanding that during the SSL handshake, the client will (normally) ...
2
votes
2answers
700 views
OpenSSH default/preferred ciphers, hash, etc for SSH2
When using OpenSSH server (sshd) and client (ssh), what are all of the default / program preferred ciphers, hash, etc. (security related) and their default options (such as key length)?
So, what are ...
2
votes
1answer
43 views
AES in CTR mode with same random IV to create same ciphertext
I am currently working on a little project.
I am trying to generate an AES key with that I would like to encrypt a private RSA key. I have to do it this way. However, I do not want to save the AES ...
2
votes
1answer
52 views
Does ciphersuite ECDH / ECDHE need hardware acceleration
I have started to read more about ECDH/ECDHE and am wondering if it has the similary issues as RSA - i.e. the processing power required for the decryption of private key is more than of the public ...
1
vote
1answer
301 views
How does Cipher Block Chaining relate to AES?
I was reading FIPS197 for a class (found here: http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf ) trying to find some sort of specific relation between CBC and AES. I guess my problem is ...
1
vote
1answer
71 views
Ciphertext for email vs Ciphertext for database
Let's say Bob wants to send a message to Alice. This communication requires to achieve confidentiality, integrity, proof of origin, non-repudiation. Therefore we can use this cipher-text:
ciphertext ...
-2
votes
1answer
182 views
Cascading Encryption Algorithm using mcrypt or GnuGP
I'm trying to a cascading cipher encryption algorithm to encrypt a textfile via mcrypt. I'm essentially trying to emulate the behavior of TrueCrypt, where it can cascade two or three different cipher ...
