A function for one block of bits in a hash function is referred to as a compression function.
RQ 2
The main arithmetic and logical functions in SHA algorithms include AND, OR, NOT, XOR and the circular shift.
RQ 3
The requirement in the replacement of a hash function is to remove the existing hash function and the insertion of the desired function.
RQ 4
A one-way function is an algorithm or a function that is used to turn a piece of text into a fixed string of digits and is nearly impossible to reverse the process. In cryptography, a one-way function is used to create digital signatures which are used to identify, and authenticate the sender and the message.
RQ 5
The Deffie Hellman key exchange uses the simple concept of prime numbers to generate a list of security keys for use in public …show more content…
Where m is the number of n-bit in the input.
21.5 A
To implement the alternative HMAC structure in figure 21.9: the zeros should be appended to the left side of k to create. XOR using iPad to have b-bit block. Append m to the bit block and thereafter apply H to have the output results.
B
With such an arrangement of HMAC as that shown in figure 21.4, the attacker is able to compute an output of compression function even if the IV is unknown, random or secrete to the attacker.
21.6
To perform encryption and decryption using RSA algorithm:
1. Select two prime numbers: p and q
2. Calculate for n where n = pq
3. Calculate for the function of n where f(n) = (p-1)(q-1)
4. Select a letter e that is relatively prime to the function of n
5. Find d where de mode function of n and then correct the d got.
21.9
Majority of standards and products use public-key cryptography for digital signatures and encryption. The bits for RSA has increased in length over time but still, person with the plaintext knowledge of one of the factors cannot be in a position to