Symmetric key encryption. Suppose (KeyGen,Enc,Dec) is an IND-CPA secure symmetric key en- cryption.

We define following new encryption algorithms, are the new schemes still IND-CPA secure?

If yes, briefly explain why. If you think it insecure, give an explicit attack violating the IND-CPA definition.

Recall that the intuition of IND-CPA security means the ciphertext does not leak any non-trivial information about the plaintext.

Enc1(k,m) is defined as follows: It runs Enc(k,m) and obtains c₀; then it adds a fixed padding of 1..1 at the end to stretch it to the right length (suppose c₀ is shorter). The final ciphertext will be c₀ ||1..1.