Computer Network
Q91.
What will be the cipher text produced by the following cipher function for the plain text ISRO with key k=7. [ Consider 'A'=0, 'B'=1,....'Z'=25] C_{k} (M) = (kM + 13) \mod 26Q92.
Using public key cryptography, X adds a digital signature \sigma to message M, encrypts \lt M, \sigma \gt, and sends it to Y, where it is decrypted. Which one of the following sequences of keys is used for the operations?Q98.
The total number of keys required for a set of n individuals to be able to communicate with each other using secret key and public key cryptosystems, respectively are:Q99.
In the RSA public key cryptosystem, the private and public keys are (e,n) and (d,n) respectively, where n=p*q and p and q are large primes. Besides, n is public and p and q are private. Let M be an integer such that 0 \lt M \lt n and \phi (n)= (p-1)(q-1). Now consider the following equations. I. M'=M^{e} mod \; n M=(M')^{d}mod \; n II. ed=1 mod n III. ed=1 mod \phi (n) IV. M'=M^{e}mod \; \phi (n) M=(M')^{d}mod \; \phi (n) Which of the above equations correctly represent RSA cryptosystem?