Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [rc6]

RC6 is a 128-bit block cipher, formerly an AES candidate, that makes heavy use of data-dependent rotations.

11 questions
7
votes
1 answer

What could "look for the constants that you might find in RC6" mean?

In this presentation at the 30c3 (long but extremely interesting and well-documented), Jacob Appelbaum gave this verbal advice (circa 43'30"): look for the constants that you might find in RC6 I'm trying to make sense out of that; my problem is,…
fgrieu
  • 149,326
  • 13
  • 324
  • 622
6
votes
1 answer

MARS and RC6 in CUDA

I am working on a project where I am benchmarking the 5 AES finalists (Rijndael, Twofish, Serpent, MARS and RC6) on CUDA Hardware. My problem is that I am no experienced CUDA programmer. My approach is to find open source projects that implement…
Martin
  • 163
  • 2
5
votes
3 answers

How to determine required number of rounds for RC6 cipher given custom W and B parameters?

The RC6 symmetric block cipher is parameterized with three parameters : W : The number of bits in a machine word (8 , 16 , 32 , 64) B : The number of bytes specifying key length (0 to 255) R : The number of rounds to execute (1 to 255) A data…
cookiecipher
  • 359
  • 1
  • 8
4
votes
1 answer

Notion of base2-logarithm in RC6 specification

I was reading this paper on RC6 and formally, the algorithm is defined for an arbitrary word size $w$, even though only $w=32$ was considered for the AES submission. Now the paper explicitly mentions the choice $w=24$, among others. Later on in the…
Jesko Hüttenhain
  • 143
  • 4
3
votes
2 answers

NSA appears to be fond of data-dependent rotations

The NSA appears to have chosen RC6 for securing the communication channels for its spyware[1]. I have found the choice curious as the cipher has become somewhat obscure after AES was chosen and it happens to be pretty much the only cipher with…
JulieMa
  • 31
  • 1
2
votes
3 answers

Input limitations on the RC6 cipher

RSA has limitation in input size for encryption and decryption. Can RC6 be used for encryption and decryption of files larger than 5 MB? Is there any limitation for input size? Is RC6 safe for using encryption or has it faced any attacks?
Anu Davis
  • 368
  • 1
  • 2
  • 10
1
vote
1 answer

Rivest Cipher 6 (RC6) Key Scheduler

I am trying to understand the Key Scheduler used in RC6 and I have a total of 3 questions. The RC6 Wikipedia page says that the only difference between the RC5 and RC6 key scheduler is that more words are produced from the key in RC6. In my…
tomneil
  • 21
  • 1
1
vote
1 answer

Which is best: RC5, RC6, CAST-128, LOKI97, or MARS?

Considering speed and security, which is best: RC5, RC6, CAST-128, LOKI97, or MARS? What does the scoreboard look like? (I'm asking about the abstract math concept, not related to any code implementation. However, hearing about code implementations…
Donald C. Spencer
  • 13
  • 2
1
vote
1 answer

Difference between RC2, RC4, RC5 and RC6

Can anyone point out the core differences between these ciphers?
arif
  • 137
  • 1
  • 2
  • 7
1
vote
1 answer

RC6 Key Size Understanding

I need help to understand how RC6 works. Many sites show that the maximum key size of RC6 is 2040 bits (255 Bytes). I can also have 0..255 rounds and 4 times 32bits words in the 128bit block variant or 4 times 64 bits Words in 256 bit variant. For…
Mist
  • 11
  • 1
0
votes
1 answer

What is the time complexity of the RC6 encryption?

I am confused to analyze time complexity of rc6 encryption. Please help me
Stefhanie Tendean
  • 13
  • 1