In this work, a high-throughput bitsliced AES implementation is proposed, which builds upon a new data representation scheme that exploits the parallelization capability of modern multi/many-core platforms. This representation scheme is employed as a building block to redesign all of the AES stages to tailor them for multi/many-core AES implementation. With the proposed bitsliced approach, each parallelization unit processes an unprecedented number of thirty-two 128-bit input data. Hence, a high order of prallelization is achieved by the proposed implementation technique. Based on the characteristics of this new implementation model, the ShiftRows stage can be implicitly handled through input rearrangement and is simplified to the point where its computing process can be neglected. In this implementation, costly Byte-wise operations are performed through register shift and swapping. In addition, the need for look-up table based I/O operations, which are used by the Substitute Bytes stage is eliminated through using S-box logic circuit. The S-box logic circuit is optimized to simultaneously process 32 chunks of 128-bit input data. We develop high-throughput CTR and ECB AES encryption/decryption on 6 CUDA-enabled GPUs, which achieve 1.47 and 1.38 Tbps of encryption throughput on V100 GPU, respectively.
The threats of physical side-channel attacks and their countermeasures have been widely researched. Most physical side-channel attacks rely on the unavoidable influence of computation or storage on current consumption or voltage drop on a chip. Such data-dependent influence can be exploited by, for instance, power or electromagnetic analysis. In this work, we introduce a novel non-invasive physical side-channel attack, which exploits the data-dependent changes in the impedance of the chip. Our attack relies on the fact that the temporarily stored contents in registers alter the physical characteristics of the circuit, which results in changes in the die's impedance. To sense such impedance variations, we deploy a well-known RF/microwave method called scattering parameter analysis, in which we inject sine wave signals with high frequencies into the system's power distribution network (PDN) and measure the echo of the signals. We demonstrate that according to the content bits and physical location of a register, the reflected signal is modulated differently at various frequency points enabling the simultaneous and independent probing of individual registers. Such side-channel leakage challenges the t-probing security model assumption used in masking, which is a prominent side-channel countermeasure. To validate our claims, we mount non-profiled and profiled impedance analysis attacks on hardware implementations of unprotected and high-order masked AES. We show that in the case of the profiled attack, only a single trace is required to recover the secret key. Finally, we discuss how a specific class of hiding countermeasures might be effective against impedance leakage.
The increasing complexity and cost of manufacturing monolithic chips have driven the semiconductor industry toward chiplet-based designs, where smaller, modular chiplets are integrated onto a single interposer. While chiplet architectures offer significant advantages, such as improved yields, design flexibility, and cost efficiency, they introduce new security challenges in the horizontal hardware manufacturing supply chain. These challenges include risks of hardware Trojans, cross-die side-channel and fault injection attacks, probing of chiplet interfaces, and intellectual property theft. To address these concerns, this paper presents ChipletQuake, a novel on-chiplet framework for verifying the physical security and integrity of adjacent chiplets during the post-silicon stage. By sensing the impedance of the power delivery network (PDN) of the system, ChipletQuake detects tamper events in the interposer and neighboring chiplets without requiring any direct signal interface or additional hardware components. Fully compatible with the digital resources of FPGA-based chiplets, this framework demonstrates the ability to identify the insertion of passive and subtle malicious circuits, providing an effective solution to enhance the security of chiplet-based systems. To validate our claims, we showcase how our framework detects hardware Trojans and interposer tampering.