Customisable arithmetic hardware designs

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Efficient Implementation on Low-Cost SoC-FPGAs of TLSv1.2 Protocol with ECC_AES Support for Secure IoT Coordinators

Security management for IoT applications is a critical research field, especially when taking into account the performance variation over the very different IoT devices. In this paper, we present high-performance client/server coordinators on low-cost SoC-FPGA devices for secure IoT data collection. Security is ensured by using the Transport Layer Security (TLS) protocol based on the TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 cipher suite. The hardware architecture of the proposed coordinators is based on SW/HW co-design, implementing within the hardware accelerator core Elliptic Curve Scalar Multiplication (ECSM), which is the core operation of Elliptic Curve Cryptosystems (ECC). Meanwhile, the control of the overall TLS scheme is performed in software by an ARM Cortex-A9 microprocessor. In fact, the implementation of the ECC accelerator core around an ARM microprocessor allows not only the improvement of ECSM execution but also the performance enhancement of the overall cryptosystem. The integration of the ARM processor enables to exploit the possibility of embedded Linux features for high system flexibility. As a result, the proposed ECC accelerator requires limited area, with only 3395 LUTs on the Zynq device used to perform high-speed, 233-bit ECSMs in 413 µs, with a 50 MHz clock. Moreover, the generation of a 384-bit TLS handshake secret key between client and server coordinators requires 67.5 ms on a low cost Zynq 7Z007S device

Reconfigurable elliptic curve cryptography

Elliptic Curve Cryptosystems (ECC) have been proposed as an alternative to other established public key cryptosystems such as RSA (Rivest Shamir Adleman). ECC provide more security per bit than other known public key schemes based on the discrete logarithm problem. Smaller key sizes result in faster computations, lower power consumption and memory and bandwidth savings, thus making ECC a fast, flexible and cost-effective solution for providing security in constrained environments. Implementing ECC on reconfigurable platform combines the speed, security and concurrency of hardware along with the flexibility of the software approach. This work proposes a generic architecture for elliptic curve cryptosystem on a Field Programmable Gate Array (FPGA) that performs an elliptic curve scalar multiplication in 1.16milliseconds for GF (2163), which is considerably faster than most other documented implementations. One of the benefits of the proposed processor architecture is that it is easily reprogrammable to use different algorithms and is adaptable to any field order. Also through reconfiguration the arithmetic unit can be optimized for different area/speed requirements. The mathematics involved uses binary extension field of the form GF (2n) as the underlying field and polynomial basis for the representation of the elements in the field. A significant gain in performance is obtained by using projective coordinates for the points on the curve during the computation process

Hardware implementation of elliptic curve Diffie-Hellman key agreement scheme in GF(p)

With the advent of technology there are many applications that require secure communication. Elliptic Curve Public-key Cryptosystems are increasingly becoming popular due to their small key size and efficient algorithm. Elliptic curves are widely used in various key exchange techniques including Diffie-Hellman Key Agreement scheme. Modular multiplication and modular division are one of the basic operations in elliptic curve cryptography. Much effort has been made in developing efficient modular multiplication designs, however few works has been proposed for the modular division. Nevertheless, these operations are needed in various cryptographic systems. This thesis examines various scalable implementations of elliptic curve scalar multiplication employing multiplicative inverse or field division in GF(p) focussing mainly on modular divison architectures. Next, this thesis presents a new architecture for modular division based on the variant of Extended Binary GCD algorithm. The main contribution at system level architecture to the modular division unit is use of counters in place of shift registers that are basis of the algorithm and modifying the algorithm to introduce a modular correction unit for the output logic. This results in 62% increase in speed with respect to a prototype design. Finally, using the modular division architecture an Elliptic Curve ALU in GF(p) was implemented which can be used as the core arithmetic unit of an elliptic curve processor. The resulting architecture was targeted to Xilinx Vertex2v6000-bf957 FPGA device and can be implemented for different elliptic curves for almost all practical values of field p. The frequency of the ALU is 58.8 MHz for 128-bits utilizing 20% of the device at 27712 gates which is 30% faster than a prototype implementation with a 2% increase in area utilization. The ALU was tested to perform Diffie-Hellman Key Agreement Scheme and is suitable for other public-key cryptographic algorithms

Hardware Implementations of Scalable and Unified Elliptic Curve Cryptosystem Processors

As the amount of information exchanged through the network grows, so does the demand for increased security over the transmission of this information. As the growth of computers increased in the past few decades, more sophisticated methods of cryptography have been developed. One method of transmitting data securely over the network is by using symmetric-key cryptography. However, a drawback of symmetric-key cryptography is the need to exchange the shared key securely. One of the solutions is to use public-key cryptography. One of the modern public-key cryptography algorithms is called Elliptic Curve Cryptography (ECC). The advantage of ECC over some older algorithms is the smaller number of key sizes to provide a similar level of security. As a result, implementations of ECC are much faster and consume fewer resources. In order to achieve better performance, ECC operations are often offloaded onto hardware to alleviate the workload from the servers' processors. The most important and complex operation in ECC schemes is the elliptic curve point multiplication (ECPM). This thesis explores the implementation of hardware accelerators that offload the ECPM operation to hardware. These processors are referred to as ECC processors, or simply ECPs. This thesis targets the efficient hardware implementation of ECPs specifically for the 15 elliptic curves recommended by the National Institute of Standards and Technology (NIST). The main contribution of this thesis is the implementation of highly efficient hardware for scalable and unified finite field arithmetic units that are used in the design of ECPs. In this thesis, scalability refers to the processor's ability to support multiple key sizes without the need to reconfigure the hardware. By doing so, the hardware does not need to be redesigned for the server to handle different levels of security. Unified refers to the ability of the ECP to handle both prime and binary fields. The resultant designs are valuable to the research community and industry, as a single hardware device is able to handle a wide range of ECC operations efficiently and at high speeds. Thus, improving the ability of network servers to handle secure transaction more quickly and improve productivity at lower costs

A versatile Montgomery multiplier architecture with characteristic three support

We present a novel unified core design which is extended to realize Montgomery multiplication in the fields GF(2n), GF(3m), and GF(p). Our unified design supports RSA and elliptic curve schemes, as well as the identity-based encryption which requires a pairing computation on an elliptic curve. The architecture is pipelined and is highly scalable. The unified core utilizes the redundant signed digit representation to reduce the critical path delay. While the carry-save representation used in classical unified architectures is only good for addition and multiplication operations, the redundant signed digit representation also facilitates efficient computation of comparison and subtraction operations besides addition and multiplication. Thus, there is no need for a transformation between the redundant and the non-redundant representations of field elements, which would be required in the classical unified architectures to realize the subtraction and comparison operations. We also quantify the benefits of the unified architectures in terms of area and critical path delay. We provide detailed implementation results. The metric shows that the new unified architecture provides an improvement over a hypothetical non-unified architecture of at least 24.88%, while the improvement over a classical unified architecture is at least 32.07%