Biblio
When employing biometric recognition systems, we have to take into account that biometric data are considered sensitive data. This has raised some privacy issues, and therefore secure systems providing template protection are required. Using homomorphic encryption, permanent protection can be ensured, since templates are stored and compared in the encrypted domain. In addition, the unprotected system's accuracy is preserved. To solve the problem of the computational overload linked to the encryption scheme, we present an early decision making strategy for iris-codes. In order to improve the recognition accuracy, the most consistent bits of the iris-code are moved to the beginning of the template. This allows an accurate block-wise comparison, thereby reducing the execution time. Hence, the resulting system grants template protection in a computationally efficient way. More specifically, in the experimental evaluation in identification mode, the block-wise comparison achieves a 92% speed-up on the IITD database with 300 enrolled templates.
Stochastic Computing (SC) is an alternative design paradigm particularly useful for applications where cost is critical. SC has been applied to neural networks, as neural networks are known for their high computational complexity. However previous work in this area has critical limitations such as the fully-parallel architecture assumption, which prevent them from being applicable to recent ones such as convolutional neural networks, or ConvNets. This paper presents the first SC architecture for ConvNets, shows its feasibility, with detailed analyses of implementation overheads. Our SC-ConvNet is a hybrid between SC and conventional binary design, which is a marked difference from earlier SC-based neural networks. Though this might seem like a compromise, it is a novel feature driven by the need to support modern ConvNets at scale, which commonly have many, large layers. Our proposed architecture also features hybrid layer composition, which helps achieve very high recognition accuracy. Our detailed evaluation results involving functional simulation and RTL synthesis suggest that SC-ConvNets are indeed competitive with conventional binary designs, even without considering inherent error resilience of SC.