RC5-CBC: best matching combination of block cipher and model of operation for implementing ORAM schemes

Abstract

The encryption and decryption time of semantically secure encryption techniques have a great influence on the total endto-end delay of an ORAM scheme. However, to the best of our knowledge, there is no work to study the impacts of combinations of block cipher and common model of operation on implementing semantically secure encryption techniques by comparing and analysing their execution time. This paper examines the running time of commonly used combinations of block cipher and model of operation to find the most matchable one for an ORAM scheme. We first selected the candidates of symmetric block encryption algorithms based on the existing block ciphers included in the LibTomCrypt, a popular cryptography toolkit. We second designed a comprehensive experiment in terms of prominent application scenarios of ORAM. We finally analysed the experimental results and found that the encryption algorithm of RC5-CBC outperforms others. In the end, we conclude that the RC5-CBC is the most matchable combination of block cipher and model of operation for implementing an ORAM scheme.