Abstract
Homomorphic encryption is a powerful cryptographic tool that enables secure computations on the private data. It evaluates any function for any operation securely on the encrypted data without knowing its corresponding plaintext. For original data p, c denotes the ciphertext of the original plaintext p, i.e. c = Encrypt_k(p). This is crucial for any sensitive application running in the Cloud, because we must protect data privacy even in the case when the server has falled victim to a cyber attack. The encryption scheme Encrypt_k is said to be homomorphic with respect to some set of operations O, if for any operation ∘ ∈ O one can compute Encrypt_k(p₁ ∘ p₂) from Encrypt_k(p₁) ∘ Encrypt_k(p₂). Those schemes come in three forms: somewhat, partially and fully homomorphic. In this survey, we present the state of art of the known homomorphic encryption schemes based on coding theory and polynomials.