DNA-chip-based dynamic broadcast encryption scheme with constant-size ciphertexts and decryption keys

In this paper we present DNA-DBE, a DNA-chip-based dynamic broadcast encryption scheme. In our scheme, new users can join dynamically without modification of other users' decryption keys. Either the ciphertext or the decryption key is of constant-size. Backward secrecy is achieved in DNA-DBE: if new users join the system dynamically, they will not be able to retrieve past data. The security of our scheme relies on hard biological problems, which are immune to attacks of new computing technologies in the future. There exists a special feature in DNA based cryptosystems, i.e. the set of encryption keys and the set of decryption keys have a many-to-many relationship. The implementation of more complicated DNA cryptosystems taking advantage of this special feature has been previously left as an open problem. Our DNA-DBE system is a solution to this open problem, which is also the first exploration of DNA based group-oriented encryption system.