AgEncID: Aggregate Encryption Individual Decryption of Key for FPGA Bitstream IP Cores in Cloud

TL;DR

This paper introduces a novel cryptosystem called Aggregate Encryption and Individual Decryption for FPGA bitstream security in cloud environments, enabling secure, efficient, and flexible protection of IP cores across multiple FPGA boards.

Contribution

It proposes a key aggregation-based cryptosystem that simplifies key management and enhances security for FPGA bitstreams, overcoming limitations of existing methods.

Findings

Outperforms existing techniques in resource, time, and energy efficiency

Provides robust security for FPGA bitstreams in cloud environments

Enables secure key provisioning through onboard individual decryption

Abstract

Cloud computing platforms are progressively adopting Field Programmable Gate Arrays to deploy specialized hardware accelerators for specific computational tasks. However, the security of FPGA-based bitstream for Intellectual Property, IP cores from unauthorized interception in cloud environments remains a prominent concern. Existing methodologies for protection of such bitstreams possess several limitations, such as requiring a large number of keys, tying bitstreams to specific FPGAs, and relying on trusted third parties. This paper proposes Aggregate Encryption and Individual Decryption, a cryptosystem based on key aggregation to enhance the security of FPGA-based bitstream for IP cores and to address the pitfalls of previous related works. In our proposed scheme, IP providers can encrypt their bitstreams with a single key for a set S of FPGA boards, with which the bitstreams can directly be decrypted on any of the FPGA boards in S. Aggregate encryption of the key is performed in a way which ensures that the key can solely be obtained onboard through individual decryption employing the board's private key, thus facilitating secure key provisioning. The proposed cryptosystem is evaluated mainly on Zynq FPGAs. The outcomes demonstrate that our cryptosystem not only outperforms existing techniques with respect to resource, time and energy significantly but also upholds robust security assurances.