Date of Degree
Giovanni Di Crescenzo
Information Security | Other Computer Sciences
Single Exponentiation, Multiple Exponentiations, Security, Efficiency, Delegation, Outsourcing
Group exponentiation is an important operation used in many cryptographic protocols, specifically public-key cryptosystems such as RSA, Diffie Hellman, ElGamal, etc. To expand the applicability of group exponentiation to computationally weaker devices, procedures were established by which to delegate this operation from a computationally weaker client to a computationally stronger server. However, solving this problem with a single, possibly malicious, server, has remained open since a formal cryptographic model was introduced by Hohenberger and Lysyanskaya in 2005. Several later attempts either failed to achieve privacy or only achieved constant security probability.
In this dissertation, we study and solve this problem for discrete log type groups and RSA type groups for both single and multiple (batch) exponentiations and apply our solution in several protocols. Each of our protocols satisfies natural correctness, security, privacy, and efficiency requirements, where security holds with exponentially small probability.
Khodjaeva, Matluba, "Secure and Efficient Delegation of a Single and Multiple Exponentiations to a Single Malicious Server" (2017). CUNY Academic Works.