Identify similar contents in encrypted data?
Not if the encryption algorithms work. And not even if it's the same encryption algorithm. This is a consequence of one of the properties required for an encryption algorithm to be considered secure: ciphertext indistinguishability under chosen ciphertext attack. If an adversary can send ciphertext 1 for decryption, and from that learns something about ciphertext 2 (such as a similarity in their corresponding plaintext), then this property is violated.