This paper discusses architectures for embedded security to enable various cryptographic services at low cost. To realize the large bit-lengths and complex arithmetic on an 8-bit embedded micro-controller, several hardware acceleration options for elliptic and hyperelliptic curve cryptography (ECC and HECC) are studied and systematically evaluated. Two key factors influence the performance: one is the communication interface i.e. I/O transfers between processor and co-processor and the other one is the boundary between hardware and software. Our experiments are run on an 8051 and an AVR micro-controller with the crypto co-processors implemented on a FPGA

This paper explores the area-throughput trade-off for an ASIC implementation of the advanced encryption standard (AES). Different pipelined implementations of the AES algorithm as well as the design decisions and the area optimizations that lead to a low area and high throughput AES encryption processor are presented. With loop unrolling and outer-round pipelining techniques, throughputs of 30 Gbits/s to 70 Gbits/s are achievable in a 0.18-/spl mu/m CMOS technology. Moreover, by pipelining the composite field implementation of the byte substitution phase of the AES algorithm (inner-round pipelining), the area consumption is reduced up to 35 percent. By designing an offline key scheduling unit for the AES processor the area cost is further reduced by 28 percent, which results in a total reduction of 48 percent while the same throughput is maintained. Therefore, the over 30 Gbits/s, fully pipelined AES processor operating in the counter mode of operation can be used for the encryption of data on optical links.

Security ICs are vulnerable to side-channel attacks (SCAs) that find the secret key by monitoring the power consumption and other information that is leaked by the switching behavior of digital CMOS gates. This paper describes a side-channel attack resistant coprocessor IC and its design techniques. The IC has been fabricated in 0.18µm CMOS. The coprocessor, which is used for embedded cryptographic and biometric processing, consists of four components: an Advanced Encryption Standard (AES) based cryptographic engine, a fingerprint-matching oracle, a template storage, and an interface unit. Two functionally identical coprocessors have been fabricated on the same die. The first, 'secure', coprocessor is implemented using a logic style called Wave Dynamic Digital Logic (WDDL) and a layout technique called differential routing. The second, 'insecure', coprocessor is implemented using regular standard cells and regular routing techniques. Measurement-based experimental results show that a differential power analysis (DPA) attack on the insecure coprocessor requires only 8,000 acquisitions to disclose the entire 128b secret key. The same attack on the secure coprocessor still does not disclose the entire secret key at 1,500,000 acquisitions. This improvement in DPA resistance of at least 2 orders of magnitude makes the attack de facto infeasible. The required number of measurements is larger than the lifetime of the secret key in most practical systems.

In this paper an AES crypto coprocessor that is fabricated using a 0.18-μm CMOS technology is presented. This crypto coprocessor performs the AES-128 encryption in both feedback and non-feedback modes of operation. A maximum throughput of 3.84 Gbits/s is achieved at a 330 MHz clock frequency for ECB, OFB, and CBC modes of operation. This crypto coprocessor can be programmed using the memory-mapped interface of an embedded CPU core and is tested using a LEON 32-bit (SPARC V8) processor in the ThumbPod secure system-on-chip.

This paper presents the architecture of a fully pipelined AES encryption processor on a single chip FPGA. By using loop unrolling and inner-round and outer-round pipelining techniques, a maximum throughput of 21.54 Gbits/s is achieved. A fast and an area efficient composite field implementation of the byte substitution phase is designed using an optimum number of pipeline stages for FPGA implementation. A 21.54 Gbits/s throughput is achieved using 84 block RAMs and 5177 slices of a VirtexII-Pro FPGA with a latency of 31 cycles and throughput per area rate of 4.2 Mbps/Slice.

Summary form only given. Coarse-grain reconfigurable systems offer high performance and energy-efficiency, provided an efficient run-time reconfiguration mechanism is available. Using an embedded software vantage point, we define three levels of reconfigurability for such systems, each with a different degree of coupling between embedded software and reconfigurable hardware. We classify reconfigurable systems starting with tightly-coupled coprocessors and evolving to processor networks. This results in a gradual increase of energy-efficiency when compared to software-only systems, at the cost of increasing programming complexity. Using several sample applications including signal-, crypto-, and network-processing acceleration units, we demonstrate energy-efficiency improvements of 12 times over software for tightly-coupled systems up to 84 times for network-on-chip systems.

This paper describes a case study and design flow of a secure embedded system called ThumbPod, which uses cryptographic and biometric signal processing acceleration. It presents the concept of HW/SW acceleration transparency, a systematic method to accelerate Java functions in both software and hardware. An example of acceleration transparency for a Rijndael encryption function is presented. The embedded prototype hardware platform is also described. Acceleration transparency yields software and hardware performance gains of 333X.