Rotational Cryptanalysis of MORUS

MORUS is one of the finalists of the CAESAR competition. This is an ARX construction that required investigation against rotational cryptanalysis. We investigated the power of rotational cryptanalysis against MORUS. We show that all the operations in the state update function of MORUS maintain the rotational pairs when the rotation distance is set to a multiple of the sub-word size. Our investigation also confirms that the rotational pairs can be used as distinguishers for the full version of MORUS if the constants used in MORUS are rotational-invariant. However, the actual constants used in MORUS are not rotational-invariant. The introduction of such constants in the state update function breaks the symmetry of the rotational pairs. Experimental results show that rotational pairs can be used as distinguishers for only one step of the initialization phase of MORUS. For more than one step, there are not enough known differences in the rotational pairs of MORUS to provide an effective distinguisher. This is due to the XOR-ing of the constants that are not rotational-invariant. Therefore, it is unlikely for an adversary to construct a distinguisher for the full version of MORUS by observing the rotational pairs.

Size, allomorphy and guttural-final stems in Modern Hebrew

There is a tendency for syncretism between future and infinitive stems in Modern Hebrew. Verbs with final orthographic gutturals do not follow this trend in one verbal type. In another, they do follow it, but their exponent is different from that of regular verbs. Previous studies have claimed that (i) gutturals are represented in Modern Hebrew as a vowel /a/ (Faust, Noam. 2005. The fate of gutturals in Modern Hebrew. Tel Aviv: Tel Aviv University MA Thesis); (ii) Infinitives are derived in two cycles (Faust, Noam & Vered Silber-Varod. 2014. Distributed Morphology and prosody: The case of prepositions. In Burit Melnik (ed.), Proceedings of IATL29 (MITWPL 72), 71–92. Cambridge (MA): MIT Press); and (iii) stems seek to be no shorter than two syllables (e.g. Bat-El, Outi. 2003. The fate of the consonantal root and the binyan in Optimality Theory. Recherches Linguistiques de Vincennes 32. 31–60.). Relying on these claims, an analysis is proposed involving two allomorphs with a priority relation. Phonological considerations of multiple correspondence, word size and cyclicity may nevertheless override the effect of priority, leading to the selection of the non-default allomorph. In the last section I briefly discuss two alternatives to the priority relation: the autosegmental alternative and the gradient alternative.

Vocabulary Size of University of Aden English Language Students

This research paper tried to evaluate the department of English students' vocabulary size by using Nation Vocabulary size tests (VST). The study used a sample of the third level students at the department of English-Faculty of Education-Aden at the University of Aden in three categories according to their academic achievement in the class (High =80-100, Medium= 70-79.99 and Low =less than 69.99). To measure the vocabulary size, the researcher used on Nation and Beglar (2007) (14000) vocabulary size test. Based on the analysis of students correct answers in the VST, the study found that students' vocabulary size ranges between 1000-8000 words with variant percentages. It was found that (80%) of third level students vocabulary size (high 08-100 and medium 70-79.99) is in the range (1000-3000), (76%) of third level students vocabulary size (high 08-100) is in the range (1000-5000) and (51%) are in the range (1000-8000). The study found that (59%) of third level students (medium 70-79.99) are in the range (1000-5000) and (40%) of them are in the range (1000-8000). The third level students (low, less than 69.99) recorded the lowest size by (50%) in the range (1000-3000), (41%) in the range (1000-5000) and only (21%) are in the range (1000-8000). Considering the total word size of the three categories together, the study found that (70%) are in the range (1000-3000), (59%) range in the range (1000-5000) and (37%) are in the range (1000-8000).

Design and Implementation of 256 Bit Modified Square Root Carry Select Adder for Area and Delay Reduction

This paper models the behaviour of modified Square Root Carry Select Adder and goes deep to investigate on its scope of reducing area and delay. This helps to overcome the drawback of conventional RCA by performing operations simultaneously for both Cin = 0 and Cin = 1, and the output is multiplexed to obtain the desired response. The work explores opportunities to reduce the area with introduction of BEC logic instead of second block RCA. The implementation of a 4 bit MCSLA and its capability of extending its word size to 8, 16, 32, 64, 128 and 256 bits are presented. The experimental result helps to verify the effectiveness of the approach. This provides understanding on how the reduction of area can bring vital improvements in Very Large Scale Integration.

Fast implementations of ARX-based lightweight block ciphers (SPARX, CHAM) on 32-bit processor

Recently, many lightweight block ciphers are proposed, such as PRESENT, SIMON, SPECK, Simeck, SPARX, GIFT, and CHAM. Most of these ciphers are designed with Addition–Rotation–Xor (ARX)-based structure for the resource-constrained environment because ARX operations can be implemented efficiently, especially in software. However, if the word size of a block cipher is smaller than the register size of the target device, it may process inefficiently in the aspect of memory usage. In this article, we present a fast implementation method for ARX-based block ciphers, named two-way operation. Moreover, also we applied SPARX-64/128 and CHAM-64/128 and estimated the performance in terms of execution time (cycles per byte) on a 32-bit Advanced RISC Machines processor. As a result, we achieved a large amount of improvement in execution time. The cycles of round function and key schedule are reduced by 53.31% and 31.51% for SPARX-64/128 and 41.22% and 19.40% for CHAM-64/128.

Phonetic structure in Yoloxóchitl Mixtec consonants

While Mixtec languages are well-known for their tonal systems, there remains relatively little work focusing on their consonant inventories. This paper provides an in-depth phonetic description of the consonant system of the Yoloxóchitl Mixtec language (Oto-Manguean, ISO 639-3 code xty), a Guerrero Mixtec variety. The language possesses a number of contrasts common among Mixtec languages, such as voiceless unaspirated stops, prenasalized stops, and a strong tendency for words to conform to a minimally bimoraic structure. Using a controlled set of data, we focus on how word size and word position influence the acoustic properties of different consonant types. We examine closure duration, VOT, and formant transitions with the stop series, spectral moments with the fricative series, the timing between oral and nasal closure with the prenasalized stop series, and both formant transitions and qualitative variability with the glide series. The general effect of word size is discussed in relation to work on polysyllabic shortening (Turk & Shattuck-Hufnagel 2000) and demonstrates the importance of prosodic templates in Mixtec languages (Macken & Salmons 1997). The prenasalized stop data provides evidence that such stops are best analyzed as allophones of nasal consonants preceding oral vowels (as per Marlett 1992) and not as hypervoiced variants of voiced stops (as per Iverson & Salmons 1996).