Problem (1)
- Alice, Bob and Charlie have a secret key a=3, b=4, c=5, respectively.
- They want to find a common secret key using Diffie-Hellan key exchange protocol (with g=2, p=5).
- Assume that there is no man-in-the-middle attacker.
- Show how they can share a common secret key with the above mentioned numbers.
Problem (2)
- Encrypt and decrypt first 3 characters of your last name (family name) using RSA with the prime numbers (p=7, q=11). (If your last name is shorter than 3 characters, use first 3 characters of your first name instead.)
- Use ASCII code at: ascii.cl
- e.g.) Michael Nordan
- A=65, B=66, ...
- N -> 78, o->111, r->72
- You can choose an encryption key e among {11, 13, 19, 23, 29} and find d.
- You have to show the all the steps (in particular, EEA) as detail as possible.
- Encrypt the message using your encryption key e like this way (n=pq):
If you number is greater than 76, decompose them into a smaller number as follows.
- e.g., 7 8 11 17 2
- (7^e) mod n
- (8^e) mod n
- (11^e) mod n
- (17^e) mod n
- (2^e) mod n
- Decryption the ciphertext using private key d.