Proof of outsourced encryption: cross verification of security service level agreement


With the popularity of cloud and edge computing, user data is often stored at third party service providers. Restricted by the available resources, end users may need to outsource the data encryption operations. However, the security service level agreement (SSLA) are usually hard to verify since it is fairly hard for end users to learn the data status at the service providers. In this paper, we investigate the proof of outsourced encryption problem. We first define the expected properties of the proof of encryption (PoE) mechanisms. Depending on the negotiated encryption algorithm in SSLA, we design two verification mechanisms so that end users can query encryption results at service providers to verify the enforcement of SSLA even when they are not aware of the keys. We formally analyze the protocols with BAN logic. Simulation and experiments show that our approaches can detect a dishonest service provider with high probability.

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Correspondence to Weichao Wang.

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On behalf of all authors, the corresponding author states that there is no conflict of interest.

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Paper Statement: This paper is an extension of the paper “Proof of Encryption: Enforcement of Security Service Level Agreement for Encryption” Alasmari et al. (2019) that was originally published in IEEE IDSC 2019. Section 1 to Section 3.3, Section 4.1 and 4.2 of the journal paper are the same as our conference paper. Section 3.4, 3.5, 4.3, and 4.4 are new contributions. The original conference paper studied the POE problem in symmetric encryption environments. The new extension focuses on the POE problem in asymmetric encryption environments, the proof of its safety, its difference from public auditing of cloud storage, and performance evaluation.

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Alasmari, S., Wang, W., Qin, T. et al. Proof of outsourced encryption: cross verification of security service level agreement. CCF Trans. Netw. 3, 229–244 (2020).

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  • Proof of Encryption
  • Security Service Level Agreement
  • User Initiated Verification