קולוקוויום במדעי המחשב - Advances in Fully Homomorphic Encryption

Abstract: 

A fully homomorphic encryption scheme scheme (FHE) is a method of encryption where an encryption of a message x can be converted into an encryption of a related message f(x), for any f, without compromising the security of the encryption. This means that data processing can be performed in an encrypted manner, without revealing the underlying information. This holds a promise for many applications such as encrypted cloud storage which can also perform computational operations on stored data without compromising its privacy. FHE had been first suggested as an idea by Rivest, Adleman and Dertouzos in 1978, but finding a candidate scheme had been a long lasting open problem, finally solved by Gentry in 2009. Since then, we have seen very rapid progress in terms of security and efficiency. 

In the talk I intend to provide some introduction to FHE and describe how to achieve FHE which is as secure as non-homomorphic encryption schemes (based on joint works with Vaikuntanathan). As much as time permits, I will also explain how to achieve an FHE scheme where different users, each with its own key, can compute a joint function of their ciphertexts without restriction on the number of users and with low space complexity (based on joint work with Perlman).