A mixnet is a multi-stage system that accepts encrypted messages as its input and generates a new altered output while exploiting cryptographic operations and repeated permutations to ensure the untraceability between the input and the output messages. Based on the employed cryptographic operations, the main types of mixnets and their variants are: decryption, re-encryption, univer-sal re-encryption and hybrid mixnets. Anonymous channel like mixnet is essential where the privacy of individual opinion is crucial.