10 Questions
How are the S-boxes in the function F represented in terms of input and output bits?
Accept 6 bits as input and produce 4 bits as output
What are the two separate 32-bit quantities labeled in the single round of a Feistel cipher?
L (left) and R (right)
In a single round of the DES algorithm, what is the formula for Ri?
Li-1 + F(Ri-1, Ki)
What is the role of S-boxes in the function F within a Feistel cipher?
Perform substitution on input bits
How are the overall processing at each round of a Feistel cipher summarized?
Li = Ri-1, Ri = Li-1 + F(Ri-1, Ki)
What is the general structure of a single round in a Feistel cipher?
Left and right halves of a 64-bit value are treated as separate 32-bit quantities
What is the calculation of Li in a single round of the DES algorithm?
Ri-1
How many bits does each S-box accept as input and produce as output?
Accepts 6 bits as input and produces 4 bits as output
What is the function of the S-boxes in the function F within a Feistel cipher?
Substitute input bits with different output bits based on a predefined table
What happens to the left and right halves of Ri-1 in a single round of DES processing?
Right half becomes the left half for the next round
Learn about the internal structure and calculations involved in a single round of the Data Encryption Standard (DES) algorithm, focusing on the left and right halves of each 64-bit intermediate value, and the formulas used in classic Feistel ciphers.
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