A protocol is given to take an ElGamal ciphertext encrypted under the key of one distributed service and produce the corresponding ciphertext encrypted under the key of another di...
Lidong Zhou, Michael A. Marsh, Fred B. Schneider, ...
Assuming a cryptographically strong cyclic group G of prime order q and a random hash function H, we show that ElGamal encryption with an added Schnorr signature is secure against ...