Semantic Security

Semantic security is a concept in cryptography that refers to the level of security of an encryption scheme against attackers who possess significant computational resources and knowledge of the encryption algorithm. In semantic security, an attacker cannot gain any meaningful information about a plaintext message by observing its corresponding ciphertext, even if the attacker has knowledge of the encryption algorithm and a large amount of ciphertext. This means that the encryption scheme is secure even if the attacker can perform arbitrary computations on the ciphertext. Semantic security is considered to be a strong form of security, and it is a desirable property for any encryption scheme.