Skills and elements used
Asymmetric encryption principles, RSA
1) How many keys would need to be distributed in order to have private conversations among 7 participants using symmetric encryption such that any 2 participants conversations are private from the others?
2) How is non-repudiation accomplished by using asymmetric encryption?
3) Use the Euclidean algorithm to compute the gcd of 973 and 307 to receive credit you MUST show all of the intermediate r0 and r1 values.
4) Two numbers are considered to be coprime if they have a GCD of 1, determine whether the following pairs of numbers are coprime:
15, 16
38, 56
37, 49
88, 24
17, 10293
5) Euler's phi function (AKA totient) is simply the quantity of numbers from 0..m-1 that are relatively prime to m.
Calculate
Calculate
6) If (note 13, 19 are prime) what is the simple calculation for ?
7) Euler’s theorem says , for a and m that are relatively prime.
show that this is true for m = 6, a = 7
8) Assume you have an RSA key pair and .
Use the public key to encrypt: 1, 2, 3, 15
Use the private key to decrypt: 27, 17, 3, 9