Functional Encryption (FE) is an emerging cryptographic technique that enables selective computations over encrypted data. In short, it allows a user (e.g., a data analyst) with a specific functional decryption key to determine a certain result of encrypted data without gaining access to the underlying data. Generally, FE schemes provide a key generation algorithm that outputs decryption keys with remarkable capabilities. Each decryption key is associated with a function (i.e., an operation). In contrast to traditional cryptographic techniques, applying this decryption key to a ciphertext does not recover the corresponding plaintext. Instead, it recovers the result of the computation, thus keeping the initial value private.
