Questions tagged [rc5]

RC5 is a symmetric key block cipher designed by Ronald Rivest.

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Modular Addition in RC5 is linear or not?

So, far my understanding was Modular addition is non linear function which is mainly used in ARX based ciphers. While I was glancing through RC5 paper (https://link.springer.com/content/pdf/10.1007/3-...
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Breaking RC5 without rotations

I'm trying to follow Schneier's self-study course in cryptanalysis and am ashamed to say I am stuck on the very first problem of breaking 8-round RC5 without any rotations (i.e. just XOR and modular ...
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Difference between RC2, RC4, RC5 and RC6

Can anyone point out the core differences between RC variations?
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100 views

Why is variable rotation uncommon in cryptographic primitives?

Most cryptographic primitives I've seen rotate by a constant. RC5 did something different though: For a word size $w=2^n$, you can take the last $n$ bits of a value as a rotation amount. There's more ...
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493 views

How to calculate initial RC5 encryption parameters?

I learn from a minithesis to understand RC5. As we can see at the formula, the round 0 must be using A=A+S[0], because the loop is starting at r(round) 1. I tried addition and OR(bitwise) to get the ...
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RC2, RC4, RC5 key length

While reading the Wiki page on RC4 I noticed that the key size must be in the range of 40–2,048 bits. So should I understand like this, that I can have a key that has length of, lets say 333 bits? (...