Question

RC5 uses 2 magic constants to define their subkeys. These are

(a) Base of natural Logarithm and Golden ratio

(b) Base of natural Logarithm and Pi

(c) Golden Ratio and  Pi

(d) Pi and Golden Ration

The question was asked by my school principal while I was bunking the class.

Origin of the question is Overview in section Cryptography Overview, TCP/IP and Communication Networks of Cryptograph & Network Security

Answer 1

Right option is (a) Base of natural Logarithm and Golden ratio

Explanation: The initialize operations makes use of magic constants defined as follows:

P_w=Odd[(e-2) 2^w]

Q_w=Odd[(φ-1) 2^w].