Bit-level pipelined digit serial GF(2m) multiplier

A low latency digit serial multiplier for GF(2m) that can be pipelined to the bit-level is presented in this paper. Unlike existing structures, the new multiplier does not put any restriction on the type of generator polynomial used or the digit size. Furthermore, the latency of the new multiplier is significantly less than the latency of the existing bit-level pipelined digit-serial multiplie

Hardware Implementations for Symmetric Key Cryptosystems

The utilization of global communications network for supporting new electronic applications is growing. Many applications provided over the global communications network involve exchange of security-sensitive information between different entities. Often, communicating entities are located at different locations around the globe. This demands deployment of certain mechanisms for providing secure communications channels between these entities. For this purpose, cryptographic algorithms are used by many of today\u27s electronic applications to maintain security. Cryptographic algorithms provide set of primitives for achieving different security goals such as: confidentiality, data integrity, authenticity, and non-repudiation. In general, two main categories of cryptographic algorithms can be used to accomplish any of these security goals, namely, asymmetric key algorithms and symmetric key algorithms. The security of asymmetric key algorithms is based on the hardness of the underlying computational problems, which usually require large overhead of space and time complexities. On the other hand, the security of symmetric key algorithms is based on non-linear transformations and permutations, which provide efficient implementations compared to the asymmetric key ones. Therefore, it is common to use asymmetric key algorithms for key exchange, while symmetric key counterparts are deployed in securing the communications sessions. This thesis focuses on finding efficient hardware implementations for symmetric key cryptosystems targeting mobile communications and resource constrained applications. First, efficient lightweight hardware implementations of two members of the Welch-Gong (WG) family of stream ciphers, the WG$\left(29,11\right)$ and WG-$16$, are considered for the mobile communications domain. Optimizations in the WG$\left(29,11\right)$ stream cipher are considered when the $GF\left(2^{29}\right)$ elements are represented in either the Optimal normal basis type-II (ONB-II) or the Polynomial basis (PB). For WG-$16$, optimizations are considered only for PB representations of the $GF\left(2^{16}\right)$ elements. In this regard, optimizations for both ciphers are accomplished mainly at the arithmetic level through reducing the number of field multipliers, based on novel trace properties. In addition, other optimization techniques such as serialization and pipelining, are also considered. After this, the thesis explores efficient hardware implementations for digit-level multiplication over binary extension fields $GF\left(2^{m}\right)$. Efficient digit-level $GF\left(2^{m}\right)$ multiplications are advantageous for ultra-lightweight implementations, not only in symmetric key algorithms, but also in asymmetric key algorithms. The thesis introduces new architectures for digit-level $GF\left(2^{m}\right)$ multipliers considering the Gaussian normal basis (GNB) and PB representations of the field elements. The new digit-level $GF\left(2^{m}\right)$ single multipliers do not require loading of the two input field elements in advance to computations. This feature results in high throughput fast multiplication in resource constrained applications with limited capacity of input data-paths. The new digit-level $GF\left(2^{m}\right)$ single multipliers are considered for both the GNB and PB. In addition, for the GNB representation, new architectures for digit-level $GF\left(2^{m}\right)$ hybrid-double and hybrid-triple multipliers are introduced. The new digit-level $GF\left(2^{m}\right)$ hybrid-double and hybrid-triple GNB multipliers, respectively, accomplish the multiplication of three and four field elements using the latency required for multiplying two field elements. Furthermore, a new hardware architecture for the eight-ary exponentiation scheme is proposed by utilizing the new digit-level $GF\left(2^{m}\right)$ hybrid-triple GNB multipliers

High Speed and Low-Complexity Hardware Architectures for Elliptic Curve-Based Crypto-Processors

The elliptic curve cryptography (ECC) has been identified as an efficient scheme for public-key cryptography. This thesis studies efficient implementation of ECC crypto-processors on hardware platforms in a bottom-up approach. We first study efficient and low-complexity architectures for finite field multiplications over Gaussian normal basis (GNB). We propose three new low-complexity digit-level architectures for finite field multiplication. Architectures are modified in order to make them more suitable for hardware implementations specially focusing on reducing the area usage. Then, for the first time, we propose a hybrid digit-level multiplier architecture which performs two multiplications together (double-multiplication) with the same number of clock cycles required as the one for one multiplication. We propose a new hardware architecture for point multiplication on newly introduced binary Edwards and generalized Hessian curves. We investigate higher level parallelization and lower level scheduling for point multiplication on these curves. Also, we propose a highly parallel architecture for point multiplication on Koblitz curves by modifying the addition formulation. Several FPGA implementations exploiting these modifications are presented in this thesis. We employed the proposed hybrid multiplier architecture to reduce the latency of point multiplication in ECC crypto-processors as well as the double-exponentiation. This scheme is the first known method to increase the speed of point multiplication whenever parallelization fails due to the data dependencies amongst lower level arithmetic computations. Our comparison results show that our proposed multiplier architectures outperform the counterparts available in the literature. Furthermore, fast computation of point multiplication on different binary elliptic curves is achieved

Throughput/Area-efficient ECC Processor Using Montgomery Point Multiplication on FPGA

High throughput while maintaining low resource is a key issue for elliptic curve cryptography (ECC) hardware implementations in many applications. In this brief, an ECC processor architecture over Galois fields is presented, which achieves the best reported throughput/area performance on field-programmable gate array (FPGA) to date. A novel segmented pipelining digit serial multiplier is developed to speed up ECC point multiplication. To achieve low latency, a new combined algorithm is developed for point addition and point doubling with careful scheduling. A compact and flexible distributed-RAM-based memory unit design is developed to increase speed while keeping area low. Further optimizations were made via timing constraints and logic level modifications at the implementation level. The proposed architecture is implemented on Virtex4 (V4), Virtex5 (V5), and Virtex7 (V7) FPGA technologies and, respectively, achieved throughout/slice figures of 19.65, 65.30, and 64.48 (106/(Seconds × Slices))

High Speed and Low Latency ECC Implementation over GF(2m) on FPGA

In this paper, a novel high-speed elliptic curve cryptography (ECC) processor implementation for point multiplication (PM) on field-programmable gate array (FPGA) is proposed. A new segmented pipelined full-precision multiplier is used to reduce the latency, and the Lopez-Dahab Montgomery PM algorithm is modified for careful scheduling to avoid data dependency resulting in a drastic reduction in the number of clock cycles (CCs) required. The proposed ECC architecture has been implemented on Xilinx FPGAs' Virtex4, Virtex5, and Virtex7 families. To the best of our knowledge, our single- and three-multiplier-based designs show the fastest performance to date when compared with reported works individually. Our one-multiplier-based ECC processor also achieves the highest reported speed together with the best reported area-time performance on Virtex4 (5.32 μs at 210 MHz), on Virtex5 (4.91 μs at 228 MHz), and on the more advanced Virtex7 (3.18 μs at 352 MHz). Finally, the proposed three-multiplier-based ECC implementation is the first work reporting the lowest number of CCs and the fastest ECC processor design on FPGA (450 CCs to get 2.83 μs on Virtex7)

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%

Error Detecting Dual Basis Bit Parallel Systolic Multiplication Architecture over GF(2m)

An error tolerant hardware efficient very large scale integration (VLSI) architecture for bit parallel systolic multiplication over dual base, which can be pipelined, is presented. Since this architecture has the features of regularity, modularity and unidirectional data flow, this structure is well suited to VLSI implementations. The length of the largest delay path and area of this architecture are less compared to the bit parallel systolic multiplication architectures reported earlier. The architecture is implemented using Austria Micro System's 0.35 m CMOS (complementary metal oxide semiconductor) technology. This architecture can also operate over both the dual-base and polynomial base

Fast Elliptic Curve Cryptographic Processor Architecture Based On Three Parallel GF(2k) Bit Level Pipelined Digit Serial Multipliers

Unusual processor architecture for elliptic curve encryption is proposed in this paper. The architecture exploits projective coordinates (x=X/Z, y=Y/Z) to convert GF(2k) division needed in elliptic point operations into several multiplication steps. The processor has three GF(2k) multipliers implemented using bit-level pipelined digit serial computation. It is shown that this results in a faster operation than using fully parallel multipliers with the added advantage of requiring less area. The proposed architecture is a serious contender for implementing data security systems based on elliptic curve cryptography