200 research outputs found

    Synthesis and Optimization of Reversible Circuits - A Survey

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    Reversible logic circuits have been historically motivated by theoretical research in low-power electronics as well as practical improvement of bit-manipulation transforms in cryptography and computer graphics. Recently, reversible circuits have attracted interest as components of quantum algorithms, as well as in photonic and nano-computing technologies where some switching devices offer no signal gain. Research in generating reversible logic distinguishes between circuit synthesis, post-synthesis optimization, and technology mapping. In this survey, we review algorithmic paradigms --- search-based, cycle-based, transformation-based, and BDD-based --- as well as specific algorithms for reversible synthesis, both exact and heuristic. We conclude the survey by outlining key open challenges in synthesis of reversible and quantum logic, as well as most common misconceptions.Comment: 34 pages, 15 figures, 2 table

    Symmetric Cryptosystem Based on Petri Net

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    يتضمن هذا البحث طريقة جديدة  تعتمد على شبكة بتري لتوليد مفتاح سري خاص .يستخدم  مؤشر الوصول الذي يشير الى البيانات الموجودة  في الشبكة كمفتاح للتشفير وفك التشفير للحصول على مفتاح معقد بشكل جيد. يستخدم كلا الطرفين (المرسل والمستقبل)  للتشفير وفك التشفيرشبكة ذات تصميم مطابق لتوليد نفس المفتاح . يتم اعادة ترتيب النص الصريح باستخدام جدول معين قبل عملية التجميع مع المفتاح لتوليد النص المشفرIn this wok, a novel approach based on ordinary Petri net is used to generate private key . The reachability marking  of petri net is used as encryption/decryption key to provide more complex key . The same ordinary Petri Nets models  are used for the sender(encryption) and  the receiver(decryption).The plaintext has been permutated  using  look-up table ,and XOR-ed with key to generate cipher tex

    Assembly or Optimized C for Lightweight Cryptography on RISC-V?

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    A major challenge when applying cryptography on constrained environments is the trade-off between performance and security. In this work, we analyzed different strategies for the optimization of several candidates of NIST\u27s lightweight cryptography standardization project on a RISC-V architecture. In particular, we studied the general impact of optimizing symmetric-key algorithms in assembly and in plain C. Furthermore, we present optimized implementations, achieving a speed-up of up to 81% over available implementations, and discuss general implementation strategies

    Fast and Robust Vectorized In-Place Sorting of Primitive Types

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    Modern CPUs provide single instruction-multiple data (SIMD) instructions. SIMD instructions process several elements of a primitive data type simultaneously in fixed-size vectors. Classical sorting algorithms are not directly expressible in SIMD instructions. Accelerating sorting algorithms with SIMD instruction is therefore a creative endeavor. A promising approach for sorting with SIMD instructions is to use sorting networks for small arrays and Quicksort for large arrays. In this paper we improve vectorization techniques for sorting networks and Quicksort. In particular, we show how to use the full capacity of vector registers in sorting networks and how to make vectorized Quicksort robust with respect to different key distributions. To demonstrate the performance of our techniques we implement an in-place hybrid sorting algorithm for the data type int with AVX2 intrinsics. Our implementation is at least 30% faster than state-of-the-art high-performance sorting alternatives

    RISC-V Instruction Set Extensions for Lightweight Symmetric Cryptography

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    The NIST LightWeight Cryptography (LWC) selection process aims to standardise cryptographic functionality which is suitable for resource-constrained devices. Since the outcome is likely to have significant, long-lived impact, careful evaluation of each submission with respect to metrics explicitly outlined in the call is imperative. Beyond the robustness of submissions against cryptanalytic attack, metrics related to their implementation (e.g., execution latency and memory footprint) form an important example. Aiming to provide evidence allowing richer evaluation with respect to such metrics, this paper presents the design, implementation, and evaluation of one separate Instruction Set Extension (ISE) for each of the 10 LWC final round submissions, namely Ascon, Elephant, GIFT-COFB, Grain-128AEADv2, ISAP, PHOTON-Beetle, Romulus, Sparkle, TinyJAMBU, and Xoodyak; although we base the work on use of RISC-V, we argue that it provides more general insight
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