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Unsafe at any key size

Published on Jan 1, 2000
Jesse Walker1
Estimated H-index: 1
A teaching machine system for displaying selected frames from a multiple-frame film strip wherein instructional material is contained on a first portion of each frame and code indicia including an excursion instruction is contained on a second portion of each frame. The code indicia associated with a frame being displayed render selected answer keys operative whereby a student selects an answer, and establish an initial counting state in a counter, which is counted down as the frames of the film strip pass a projection gate in proceeding to the next frame to be viewed. When the counter reaches a predetermined minimum counting state, dependent on the particular answer key selected by the student, the film strip is stopped and the next frame is viewed. An alternate mode of operation is provided wherein fixed excursions of a predetermined number of frames occur for each answer key. A dynamic reading method is employed for reading code indicia on the film strip to reduce the number of photodetectors required. A performance memory is provided for branching to advanced material after a predetermined number of correct answers, and a no-go circuit is provided for discouraging frivolous or improper depression of answer keys. The film transport includes a self-threading feature, and operates at two speeds to reduce excursion time and to provide a smooth controlled stop sequence. A novel cassette-type supply reel provides automatic mode selection, and novel reel hub assemblies provide for bidirectional film movement with a single bidirectional drive motor.
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  • Citations (11)
Cited By11
Published on Jan 1, 2007
Razvi Doomun5
Estimated H-index: 5
(University of Mauritius)
A device for treating aqueous solutions with magnetic lines of force includes a pipe through which the solution passes. An electromagnetic coil surrounds the pipe and a core consisting of endwise connected alternating short sections of magnetic and nonmagnetic material is disposed along the pipe's axis. Located between the pipe and the core is a helical baffle.
Published on Jan 1, 2007
Minghui Shi10
Estimated H-index: 10
(University of Waterloo),
Humphrey Rutagemwa10
Estimated H-index: 10
(University of Waterloo)
+ 3 AuthorsChuang Lin34
Estimated H-index: 34
(Tsinghua University)
A wireless LAN service integration architecture based on current wireless LAN hotspots is proposed to make migrating to new service cost effective. The AAA (Authentication, Authorization and Accounting) based mobile terminal registration signaling process is discussed. An application layer end-to-end authentication and key negotiation protocol is proposed to overcome the open air connection problem existing in wireless LAN deployment. The protocol provides a general solution for Internet applica...
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Neil Smyth3
Estimated H-index: 3
Máire McLoone15
Estimated H-index: 15
John V. McCanny26
Estimated H-index: 26
A novel wireless local area network (WLAN) security processor is described in this paper. It is designed to offload security encapsulation processing from the host microprocessor in an IEEE 802.11i compliant medium access control layer to a programmable hardware accelerator. The unique design, which comprises dedicated cryptographic instructions and hardware coprocessors, is capable of performing wired equivalent privacy, temporal key integrity protocol, counter mode with cipher block chaining m...
9 Citations Source Cite
Published on Jan 1, 2006
Jeyanthi Hall7
Estimated H-index: 7
(Carleton University)
The need for robust access control mechanisms is paramount, especially in Wireless Local Area Network (WLAN)s and Wireless Wide Area Network (WWAN)s. Current authentication systems are vulnerable to device impersonation by rogue devices. Within cellular mobile networks, this threat is actualized by cloning cell phones, and using the clones for obtaining free services. A well known example in Wireless Fidelity (WiFi)/802.11 networks is Media Access Control (MAC) address spoofing. In this case, an...
18 Citations
Song-Kong Chong1
Estimated H-index: 1
Hsien-Chu Wu1
Estimated H-index: 1
Chia-Chun Wu3
Estimated H-index: 3
Wired equivalent privacy encryption of IEEE 802.11 standard is based on the RC4 stream cipher, but the weakness in its Initialization Vector (IV) derivation causes the Key Scheduling Algorithm (KSA) of RC4 to leak out the information about the secret key. It is shared among the particular participants in the Wireless LAN (WLAN). Housley et al. proposed an Alternate Temporal Key Hash (ATKH) to solve the weakness of the KSA; they defeated the particular IV may make the KSA to leak out the informat...
3 Citations Source Cite
Published on Jan 1, 2005
Steve Glass5
Estimated H-index: 5
(Griffith University),
Vallipuram Muthukkumarasamy17
Estimated H-index: 17
This paper addresses denial of service vulnerabilities (DOS) in 802.11 wireless LANs that arise from the 802.11 distributed coordination function (DCF). We demonstrate that the DCF is vulnerable to equivalent DOS attacks at both the MAC and PHY layers. Denial of service attacks against the DCF are easily staged by a single adversary and affect both infrastructure and mobile ad hoc networks. These attacks are very effective and there are no workable counter-measures when using the standard MAC pr...
2 Citations
Published on Aug 1, 2004in ACM Transactions in Embedded Computing Systems 1.16
Taejoon Park10
Estimated H-index: 10
(University of Michigan),
Kang G. Shin80
Estimated H-index: 80
(University of Michigan)
Small low-cost sensor devices with limited resources are being used widely to build a self-organizing wireless network for various applications, such as situation monitoring and asset surveillance. Making such a sensor network secure is crucial to their intended applications, yet challenging due to the severe resource constraints in each sensor device. We present a lightweight security protocol (LiSP) that makes a tradeoff between security and resource consumption via efficient rekeying. The hea...
112 Citations Source Cite
Published on May 1, 2004 in IEEE Symposium on Security and Privacy
David Johnston2
Estimated H-index: 2
Jesse Walker11
Estimated H-index: 11
When creating the new wireless communication standard IEEE 802.16, designers attempted to reuse a security scheme designed for wired media. The authors review the standard, enumerate its flaws, and outline changes that could defend it against threats.
188 Citations Source Cite