201,722 research outputs found
Performance Analysis of Modified SHA-3
No full textAbstractSecurity services have become an inseparable feature of almost all digital transactions. A crucial module of these scheme isintegrity, which is performed using a cryptographic hash function. Secure Hash Algorithm can be an efficient hashing technique.SHA-3 is the most recent and efficient Secure Hash Algorithm. Keccak has been chosen as the official algorithm for SHA-3 in2012. In this paper we propose a modification on the design of Secure Hash Algorithm (SHA-3) on Xilinx Field ProgrammableGate Array (FPGA) device. In order to provide reliable architecture for this algorithm, a concurrent error tolerant scheme forSHA-3 is used. A system based on the combination of SHA-3 and error tolerant scheme is also described. Simulation resultsshows, an efficiency in area and delay of SHA-3 designs
Efficient single-chip implementation of SHA-384 and SHA-512
No full textThe rapid developments in the communications industry over the last decade have led to an escalation in the amount of sensitive data being transmitted over the Internet. This has resulted in an increased awareness of the need to provide security measures. Authentication is one such security measure. A novel highly efficient single-chip hardware design of the SHA-384 and SHA-512 authentication algorithms is described in this paper. The compact implementation achieves a throughput of 479 Mbits/sec utilising a shift register design approach and look-up tables (LUTs). This is believed to be the first SHA-384/SHA-512 hardware implementation to be reported in the literature.</p
The Brauer-Manin Obstruction and Sha[2].
No full textWe discuss the Brauer-Manin obstruction on del Pezzo surfaces of degree 4. We outline a detailed algorithm for computing the obstruction and provide associated programs in magma. This is illustrated with the computation of an example with an irreducible cubic factor in the singular locus of the defining pencil of quadrics (in contrast to previous examples, which had at worst quadratic irreducible factors). We exploit the relationship with the Tate-Shafarevich group to give new types of examples of Sha[2], for families of curves of genus 2 of the form y^2 = f(x), where f(x) is a quintic containing an irreducible cubic factor
Modified SHA-1 Algorithm
No full textHashes are used to check the integrity of data. This paper modified SHA-1 by incorporating mixing method in every round for better diffusion. The modification increased the hash output to 192-bits. Increasing the output increases the strength because breaking the hash takes longer. Based on the different message types, avalanche percentage of modified SHA-1 showed better diffusion at 51.64%, higher than the target 50%, while SHA-1 achieved 46.61%. The average execution time noted for modified SHA-1 is 0.33 seconds while SHA-1 is 0.08 seconds. Time increases as the number of messages hashed increases; the difference is negligible in fewer messages. On character hits, that is - no same character in the same position, modified SHA-1 achieved lower hit rate because of the mixing method added. The modifications’ effectiveness was also evaluated using a hash test program. After inputting 1000 hashes from random strings, the result shows no duplicate hash
Analysis of step-reduced SHA-256
No full textThis is the first article analyzing the security of SHA-256 against fast collision search which considers the recent attacks by Wang et al. We show the limits of applying techniques known so far to SHA-256. Next we introduce a new type of perturbation vector which circumvents the identified limits. This new technique is then applied to the unmodified SHA-256. Exploiting the combination of Boolean functions and modular addition together with the newly developed technique allows us to derive collision-producing characteristics for step-reduced SHA-256, which was not possible before. Although our results do not threaten the security of SHA-256, we show that the low probability of a single local collision may give rise to a false sense of security. © International Association for Cryptologic Research 2006.status: Publishe
Kontruks metode tafsir al-sha�rawi , mengenal pendekatan tematik dalam tafsir al-sha�rawi
No full textterhadap ayat Al-Qur�a>n dengan ayat yang lain. Penelitian ini tidak sependapat dengan Must}afa Umar, bahwa metode yang digunakan oleh al-Sha�ra>wi> menggunakan metode�Aqliyyah Ijtima�iyyah. Must}afa Umar menjelasakan bahwa �Aqliyyah merupakan peran penting dalam penafsiran, bukan berarti meninggalkan wahyu sama sekali karena wahyu tidak bertentangan dengan akal manusia. Sedangkan Ijtima�iyyah sebagai data atau informasi untuk perbaikan masyarakat dari kemaslahatan manusia untuk kembali kepada Allah. Sedangkan menurut Muhammad �Ali> Aya>zi> mengatakan bahwa al-Sha�ra>wi> termasuk dalam katagori penafsiran al-Ra�yi>. Dalam hal ini berbeda dengan ungkapan Usman abd al-Rahi>m al-Qamihi meyatakan bahwa al-Sha�ra>wi> menggunakan metode mawd}u>�i> dalam penafsriannya dalam membahasa ayat Al-Qur�a>n pada satu tema tertentu. Penelitian ini menunjukkan bahwa sistematika penafsiran al- Sha�ra>wi> sangat berbeda dengan penafsiran lainnya, dilihat dari pemetaan terhadap tafsirnya. Dalam hal ini al-Sha�ra>wi> menggunakan metode tematik, disebabkan metode tematik merupakan hasil dari metode-metode tafsir yang bisa menjawab persoalan kekinian. Kemudian Sha�ra>wi> mengkalaborasikan dua metode tafsir yaitu tahlili dan mawd}u>�i>. Dengan Metode tematik tersebut, al-Sha�ra>wi >menggunakan satu masalah pokok yang ditemukan secara konsisten, serta membahas ayat Al-Qur�a>n yang memiliki keterkaitan dengan tema. Maka terdapat kesatuan tema terhadap ayat tersebut. Pendekatan yang digunakan dalam penelitian ini adalah pendekatan sejarah dan sosiologi. Dalam pendekatan sejarah, memberikan penyajian fakta-fakta tentang peristiwa masa lalu dan biografis al-Sha�ra>wi>. Selain itu juga menggunakan pendekatan sosiologi untuk memahami interaksiinteraksi masa lalu dan masa kini dalam sebuah masyarakat dan budaya. Data yang dihimpun merupakan pola penafsiran yang dilakukan oleh al- Sha�ra>wi> serta konsep-konsep dasar yang berkaitan dengan tafsir al- Mawd}u>�i>. Sumber utama dalam penelitian ini adalah Khawa>t}iri> hawl al- Qura>n al-Kari>m sedangkan sumber skundernya tafsir bi al-Matshu>r dan bi al-Ra�yi> serta semua tulisan yang sesuai dengan tema yang dikaji
Sha-Ho-Kou
No full textSHA-HO-KOU
Map of portions of Chinese Turkistan and Kansu (-)
Sha-Ho-Kou (Sheet No. 93) ( -
Sha-Chüan-Tzŭ
No full textSHA-CHÜAN-TZŬ
Map of portions of Chinese Turkistan and Kansu (-)
Sha-Chüan-Tzŭ (Sheet No. 77) ( -
113. Meiroku-sha
No full textIwao Seiichi, Iyanaga Teizō, Ishii Susumu, Yoshida Shōichirō, Fujimura Jun'ichirō, Fujimura Michio, Yoshikawa Itsuji, Akiyama Terukazu, Iyanaga Shōkichi, Matsubara Hideichi. 113. Meiroku-sha. In: Dictionnaire historique du Japon, volume 14, 1988. Lettres L et M (1) pp. 64-65
Security Reductions of the Second Round SHA-3 Candidates
No full text© 2011, Springer-Verlag Berlin Heidelberg. In 2007, the US National Institute for Standards and Technology announced a call for the design of a new cryptographic hash algorithm in response to vulnerabilities identified in existing hash functions, such as MD5 and SHA-1. NIST received many submissions, 51 of which got accepted to the first round. At present, 14 candidates are left in the second round. An important criterion in the selection process is the SHA-3 hash function security and more concretely, the possible security reductions of the hash function to the security of its underlying building blocks. While some of the candidates are supported with firm security reductions, for most of the schemes these results are still incomplete. In this paper, we compare the state of the art provable security reductions of the second round SHA-3 candidates. Surprisingly, we derive some security bounds from the literature, which the hash function designers seem to be unaware of. Additionally, we generalize the well-known proof of collision resistance preservation, such that all SHA-3 candidates with a suffix-free padding are covered.sponsorship: This work has been funded in part by the IAP Program P6/26 BCRYPT of the Belgian State (Belgian Science Policy), and in part by the European Commission through the ICT program under contract ICT-2007- 216676 ECRYPT II. The first author is supported by a Ph.D. Fellowship from the Flemish Research Foundation (FWO-Vlaanderen). The second author is supported by a Ph.D. Fellowship from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). (IAP of the Belgian State (Belgian Science Policy|P6/26 BCRYPT, European Commission through the ICT program|ICT-2007- 216676, Flemish Research Foundation (FWO-Vlaanderen), Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen))status: Publishe
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