We analyze the generation and management of 802.11 group keys. These keys protect broadcast and multicast Wi-Fi traffic. We discovered several issues and illustrate their importance by decrypting all group (and unicast) traffic of a typical Wi-Fi network. First we argue that the 802.11 random number generator is flawed by design, and provides an insufficient amount of entropy. This is confirmed...

We describe some observed trivially weak keys for the stream cipher RC4. Keys with repeating patterns are found to be key length invariant. The cause of the problem is the simplistic key dependent state permutation in the RC4 initialization. Introduction While writing the draft for RFC 6229 [1] and testing suitable test vectors, we observed that for some keys with different lengths, the stream ...

The Wired Equivalent Privacy (WEP) uses the 64 bit RC4 secret key stream cipher as its layer 2 security protocol. Although the underlying RC4 cipher is secure, the potential reuse of the same key stream by different frames is a weakness in the WEP. One enhancement to WEP is the Temporal Key Integrity Protocol (TKIP), which acts as a wrapper to the WEP protocol and uses a 128 bit RC4 encryption ...

This paper reconsiders the design of the stream cipher RC4, and proposes an improved variant, which we call “Spritz” (since the output comes in fine drops rather than big blocks.) Our work leverages the considerable cryptanalytic work done on the original RC4 and its proposed variants. It also uses simulations extensively to search for biases and to guide the selection of intermediate expressio...

Since the secure communication for Wireless Sensor Network (WSNs) is a challenging problem because sensors are resources limited and cost is the most dominant factor in a energy consumption, for this we introduce an energy-efficient Virtual Energy-Based Encryption and Keying(VEBEK) scheme for WSNs that reduces the number of transmission needed for rekeying the packets. VEBEK is a secure communi...

در بررسی­های فونستیک سال 2011 دامنه جنوبی رشته کوه­های زاگرس ایران، یک نمونه ماده از گونه Amphipyra kautti Hacker, 2002 متعلق به خانواده Noctuidae و زیرخانواده Amphipyrinae مناطق کوهستانی استان کهگیلویه بویراحمد جمع­ آوری شناسایی شد. این که برای اولین بار ایران گزارش می­شود، همراه با ویژگی­های افتراقی، تصویر الگوی بال اندام تناسلی شده ارائه است. اطلاعات مربوط دیگر همین جنس مطالعه نیز

The current study sought to characterize the psychological architecture of individuals who put forth inadequate effort. The Minnesota Multiphasic Personality Inventory, 2nd Edition-Restructured Form was used to identify dimensions of psychological functioning in a mixed outpatient sample of U.S. Veterans referred for neuropsychological evaluation as part of their clinical care. After accounting...

Consider the permutation S in RC4. Roos pointed out in 1995 that after the Key Scheduling Algorithm (KSA) of RC4, the initial bytes of the permutation, i.e., S[y] for small values of y are biased towards some linear combination of secret key bytes. In this paper, for the first time we show that the bias can be observed in S[S[y]] too. Based on this new form of permuatation bias after the KSA an...

We present a new Cryptographically Secure Pseudo-Random Number Generator. It uses permutations as its internal state, similarly to the RC4 stream cipher. We describe a statistical test which revealed non-random patterns in a sample of 2 outputs of a 3-bit RC4. Our new algorithm produced 2 undistinguishable from random 3-bit outputs in the same test. We probed 2 outputs of the algorithm in diffe...