Abstract: Secure outsourced computation on data can be achieved by transmitting shares of the data to respective computation servers; establishing respective connections between each of the computation servers and respective security modules, wherein each security module contains respective security data, the security data on the security modules being related by means of a Linear Secret Sharing Scheme; computing respective shares of a computation result in the computation servers, using the respective shares of the data and the respective security data; returning the shares of the computation result to a data owner; and obtaining the computation result from the respective shares of the computation result.

Abstract: A secure communication system comprising: a communications network; at a sending location on said network: (i) an encapsulator (1) for providing (a) a session key (K), and (b) plurality of asymmetric encryptions of the session key (E1(K), E2(K), E3(K) . . . Ei(K) . . . En(K)), each said encryption corresponding to a respective receiving location (1 to n) on said network; and (ii) a symmetric encryptor (3) for utilising said session key (K) to encrypt a message (M); and, at each said receiving location (1 to n) on said network: (i) a decapsulator (5) for decrypting the encryption of said plurality of encryptions (E1(K), E2(K), E3(K) . . . Ei(K) . . .