A Second View on SecureString 2.0

Abstract

Many companies have thought about using external hosting solutions. Cloud computing as such a solution attracts prospective users who want to avoid initial costs and standing expenses with the underlying pay-as-you-use model. The outsourcing of sensitive information implies security risks, like eavesdropping and sabotage, for them as soon as they pass any unconfident area. If an outhouse hosting solution serves as data storage only, then an end-to-end cryptosystem without the necessity of having homomorphic properties comes up with the answer. Moreover, secure computations on the encrypted data need the use of more complex cryptosystems. SecureString 1.0 [3] and SecureString 2.0 [4] were proposed as such complex cryptosystems that focus on computing on encrypted character strings in untrustworthy environments (like clouds). While SecureString 1.0 offered a too inflexible approach, SecureString 2.0 as its improvement was introduced textually at a high level only so far. This paper contributes to foster the understanding of SecureString 2.0 by providing performance analysis for its supported operations plus formal definitions, theorems and proofs.