This chapter discusses the security of functionally obfuscated digital signal processing (DSP) cores. Some of the most prominent aspects of this chapter include descriptions of the attack models, points of vulnerability for launching reverse engineering (RE), security properties of the functional-obfuscation process, security against removal attack in the context of DSP cores, hardware-design methods of various state-of-the-art security solutions and a comparative perspective of different approaches used in the context of DSP cores.

Chapter Contents:

• 9.1 Introduction
• 9.2 Attack scenarios and threat models of functional obfuscation
• 9.3 Functional obfuscation of DSP cores
• 9.4 Selected approaches for securing functionally obfuscated DSP cores against removal attacks
• 9.4.1 Threat model
• 9.4.2 Discussion on selected approaches
• 9.4.2.1 Security of functionally obfuscated DSP core against removal attacks using custom AES-128-based ILBs-key generation hardware (Sengupta et al., 2019)
• 9.4.2.2 Security of functionally obfuscated DSP cores against removal attacks using custom SHA-512-based ILBs-key generation hardware (Sengupta and Rathor, 2019)
• 9.4.2.3 Security of a functionally obfuscated DSP core against removal attack using custom lightweight anti-removal logic unit (Rathor and Sengupta, 2019)
• 9.4.3 Demonstration of ILB structure reconfiguration
• 9.5 Analyses of case studies
• 9.5.1 Security analysis
• 9.5.1.1 Comparative study between obfuscated DSP core with custom SHA-512-based key encryption hardware vs. obfuscated DSP core with custom AES-128-based key encryption hardware
• 9.5.1.2 Comparative study between obfuscated DSP core with ARL unit vs. obfuscated DSP core with AES-128-based key encryption hardware
• 9.5.2 Design cost analysis: comparative study between obfuscated DSP core with SHA-512 vs. obfuscated DSP core with AES-128
• 9.5.3 Resource usage analysis: comparative study between obfuscated DSP cores with AES vs. obfuscated DSP cores with ARL unit
• 9.6 Conclusion
• 9.7 Questions and exercises
• References

Inspec keywords: digital signal processing chips; reverse engineering; security of data

Other keywords: functionally obfuscated digital signal processing cores; reverse engineering; attack models; security properties; removal attack; hardware-design methods; functionally obfuscated DSP cores

Subjects: Digital signal processing chips; Security aspects of hardware; Digital signal processing chips