I read about elgamal algorithm it work like the follow steps
- Bashir chooses a large random prime p and a primitive root α modulo p.
- Bashir then chooses a random integer a with 2 ≤ a < p - 1 and computes α^a mod p.
- Bashir’s public key is (p,α,α^a) and his private session key is a.
Enciphering stage consists of the following steps:
- Amina obtains Bashir’s public key (p,α,α^a).
- She chooses a random natural number b < p - 1.
- She computes α^b mod p and mα^ab mod p.
- Amina then sends the cipher text c = (α^b,mα^ab) to Bashir.
Deciphering stage consists of the following steps:
- Bashir uses his private key to compute (α^b )^(-a) mod p.
Then he deciphers m by computing (α^b )^(-a) .mα^ab mod p.
I understood this algorithm but I have Wondered simple
Imagine that we have a message consists of four parts (block data) and want Amina encrypted and sent to Bashir.
Is Amina used the same Private Key (b) Of four parts or generate a new private key for each part of the message During the session encryption.