Athanasios P. Kakarountas
University of Patras
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Featured researches published by Athanasios P. Kakarountas.
IEEE Transactions on Circuits and Systems | 2009
Dimitrios Schinianakis; Apostolos P. Fournaris; Harris E. Michail; Athanasios P. Kakarountas; Thanos Stouraitis
Elliptic curve point multiplication is considered to be the most significant operation in all elliptic curve cryptography systems, as it forms the basis of the elliptic curve discrete logarithm problem. Designs for elliptic curve cryptography point multiplication are area demanding and time consuming. Thus, the efficient realization of point multiplication is of fundamental importance for the performance of an elliptic curve system. In this paper, a hardware architecture of an elliptic curve point multiplier is proposed that exploits the intrinsic parallelism of the residue number system (RNS), in order to speed up the elliptic curve point calculations and minimize the area complexity of the elliptic curve point multiplier. The architecture proves to be the fastest among all known design approaches, while complexity is less than half of that of previous efforts. This architecture also supports the required input (binary-to-RNS) and output (RNS-to-binary) conversions. Through a graph-oriented approach, the area of the elliptic curve point multiplier is minimized, by optimizing the point addition and doubling algorithms. Also, through this approach, the number of execution steps for point addition is matched to the number of execution steps for point doubling. Additionally, the impact of various RNS bases, in terms of number of moduli and their bit lengths, on the area and speed of the proposed implementation is analyzed, in an effort to define the potential for using RNS in elliptic curve cryptography.
mediterranean electrotechnical conference | 2006
Dimitrios Schinianakis; Athanasios P. Kakarountas; Thanos Stouraitis
An elliptic curve point multiplier (ECPM) is the main part of all elliptic curve cryptography (ECC) systems and its performance is decisive for the performance of the overall cryptosystem. A VLSI residue number system (RNS) architecture of an ECPM is presented in this paper. In the proposed approach, the necessary mathematical conditions that need to be satisfied, in order to replace typical finite field circuits with RNS ones, are investigated. It is shown that such an application is feasible and that it leads to a significant improvement in the execution time of a scalar point multiplication
Journal of Real-time Image Processing | 2008
Markos E. Papadonikolakis; Athanasios P. Kakarountas; Costas E. Goutis
A new design approach to create an efficient high-performance JPEG-LS encoder is proposed in this paper. The proposed implementation compresses the image data with the lossless mode of JPEG-LS. When the acquisition of precious content (image) is specified to occur in real-time, then lossless compression is essential. Lossless compression is important to critical applications, such as the acquisition of medical images and transmission of high-definition high-resolution images from space (satellite). The contribution of the paper is to introduce an efficient pipelined JPEG-LS encoder, which requires significantly lower encoding time than any other available JPEG-LS hardware or software implementation. The experimental results show that encoding is performed as expected in high-speed, being able to serve real-time applications. This is the first time that a JPEG-LS implementation offers such a high-speed encoding.
international conference on electronics circuits and systems | 2004
Harris E. Michail; Athanasios P. Kakarountas; Athanasios Milidonis; Costas E. Goutis
In this paper, an efficient implementation, in terms of performance, of the keyed-hash message authentication code (HMAC) using the SHA-1 hash function is presented. This mechanism is used for message authentication in combination with a shared secret key. The proposed hardware implementation can be synthesized easily for a variety of FPGA and ASIC technologies. Simulation results, using commercial tools, verified the efficiency of the HMAC implementation in terms of performance and throughput. Special care has been taken so that the proposed implementation does not introduce extra design complexity; while in-parallel functionality was kept to the required levels.
IEEE Transactions on Dependable and Secure Computing | 2009
Harris E. Michail; Athanasios P. Kakarountas; Athanasios Milidonis; Costas E. Goutis
Many cryptographic primitives that are used in cryptographic schemes and security protocols such as SET, PKI, IPSec, and VPNs utilize hash functions, which form a special family of cryptographic algorithms. Applications that use these security schemes are becoming very popular as time goes by and this means that some of these applications call for higher throughput either due to their rapid acceptance by the market or due to their nature. In this work, a new methodology is presented for achieving high operating frequency and throughput for the implementations of all widely used-and those expected to be used in the near future-hash functions such as MD-5, SHA-1, RIPEMD (all versions), SHA-256, SHA-384, SHA-512, and so forth. In the proposed methodology, five different techniques have been developed and combined with the finest way so as to achieve the maximum performance. Compared to conventional pipelined implementations of hash functions (in FPGAs), the proposed methodology can lead even to a 160 percent throughput increase.
The Journal of Supercomputing | 2006
Athanasios P. Kakarountas; Haralambos Michail; Athanasios Milidonis; Costas E. Goutis; George Theodoridis
Hash functions are special cryptographic algorithms, which are applied wherever message integrity and authentication are critical. Implementations of these functions are cryptographic primitives widely used in common cryptographic schemes and security protocols such as Internet Protocol Security (IPSec) and Virtual Private Network (VPN). In this paper, a novel FPGA implementation of the Secure Hash Algorithm 1 (SHA-1) is proposed. The proposed architecture exploits the benefits of pipeline and re-timing of execution through pre-computation of intermediate temporal values. Pipeline allows division of the calculation of the hash value in four discreet stages, corresponding to the four required rounds of the algorithm. Re-timing is based on the decomposition of the SHA-1 expression to separate information dependencies and independencies. This allows pre-computation of intermediate temporal values in parallel to the calculation of other independent values. Exploiting the information dependencies, the fundamental operational block of SHA-1 is modified so that maximum operation frequency is increased by 30% approximately with negligible area penalty compared to other academic and commercial implementations. The proposed SHA-1 hash function was prototyped and verified using a XILINX FPGA device. The implementation’s characteristics are compared to alternative implementations proposed by the academia and the industry, which are available in the international IP market. The proposed implementation achieved a throughput that exceeded 2,5 Gbps, which is the highest among all similar IP cores for the targeted XILINX technology.
international symposium on circuits and systems | 2006
Dimitrios Schinianakis; Apostolos P. Fournaris; Athanasios P. Kakarountas; Thanos Stouraitis
An elliptic curve point multiplier (ECPM) is the main part of all elliptic curve cryptography (ECC) systems and its performance is decisive for the performance of the overall cryptosystem. A VLSI residue number system (RNS) architecture of an ECPM is presented in this paper. In the proposed approach, the necessary mathematical conditions that need to be satisfied, in order to replace typical finite field circuits with RNS ones, are investigated. It is shown that such an application is feasible and that it leads to a significant improvement in the execution time of a scalar point multiplication
signal processing systems | 2005
Andreas Brokalakis; Athanasios P. Kakarountas; Costas E. Goutis
Advanced Encryption Standard (AES) is used nowadays extensively in many network and multimedia applications to address security issues. In this paper, a high throughput area efficient FPGA implementation of the latter cryptographic primitive is proposed. It presents the highest performance (in terms of throughput) among competitive academic and commercial implementations. Using a Virtex-II device, a 1.94 Gbps throughput is achieved, while the memory usage remains low (8 BlockRAMs) and the CLB coverage moderate.
international conference on electronics circuits and systems | 2003
Athanasios P. Kakarountas; George Theodoridis; Kyriakos Papadomanolakis; Costas E. Goutis
Counters are among the basic blocks in every digital system. We propose a novel high-speed counter with a constant counting rate, independent of its length. Exploiting special features of the binary arithmetic system and adopting prescaling techniques, a segmented counter architecture is introduced. Particularly, to realize a counter of any length properly, two designed modules of four-bit counter are used in a systolic manner. The counting rate is bounded by the delay of two basic gates of three inputs plus the delay of a T F/F. In AMS 0.6 /spl mu/m technology a maximum of 430 MHz counting frequency is achieved.
International Journal of Security and Networks | 2007
Harris E. Michail; George A. Panagiotakopoulos; Vasilis N. Thanasoulis; Athanasios P. Kakarountas; Costas E. Goutis
Hash functions are forming a special family of cryptographic algorithms, which are applied wherever message integrity and authentication issues are critical. Implementations of these functions are cryptographic primitives to the most widely used cryptographic schemes and security protocols such as Secure Electronic Transactions (SET), Public Key Infrastructure (PKI), IPSec and Virtual Private Networks (VPNs). As time passes it seems that all these applications call for higher throughput due to their rapid acceptance by the market especially to the corresponding servers of these applications. In this work a new technique is presented for increasing frequency and throughput of the currently most used hash function, which is SHA-1. This technique involves the application of spatial and temporal precomputation. Comparing to conventional pipelined implementations of hash functions, the proposed technique leads to an implementation with more than 75% higher throughput.