Colloquium Archive

Early Supercomputers And Disassemblers

Steve Jasik, Jasik Designs, Menlo Park


Steve Jasik talks about the 1st supercomputers of the 1960's, the Control Data 6600 and 7600, and about the global disassembler MacNosy. Mr Jasik was associated with Control Data from 1967 to 1984 where he worked on the FORTRAN compiler, mostly the code optimizer. At the time the 6600 was the first computer with multiple functional units and a micro parallel architecture, it presented some unique problems for those who tried to generate code for it. In 1984 wrote the first global disassembler, MacNosy for then new Apple Macintosh computer.

When Can I Buy A 50" 1920X1080 Hdtv With High Brightness For 999$?

Mary Lou Jepsen, MicroDisplay Corp., San Pablo


MicroDisplay Corporation creates HD-resolution LCOS (liquid crystal on silicon) display chipsets for use in optical projection systems. MicroDisplay panels are capable of 500 frame per second operation allowing their use in single-panel projection systems. Single panel systems offer substantial cost and quality advantages over the three-chip (one for red, green and blue) alternatives. MicroDisplay's single paneloperation is enabled by 1) high speed electronics 2) fast, high contrast, TN liquid crystals (80 microsecond switch time) 3) ability to manufacture thin (fast) layers ofliquid crystal material at our manufacturing facility in San Pablo. This technology is about to be become widely available, and will likely find uses in other newer, currently high-end, display technologies.

Solving The Knight's Tour With A Genetic Algorithm

Vahl Scott Gordon, California State University, Sacramento


The Knight's Tour puzzle has captured the imagination of mathematicians and chessplayers for centuries. The goal is to find paths through a chessboard with standard chess knight moves, touching every square exactly once. A simple hill-climbingsolution is presented, and applied to a random population of 1 million individuals. The same framework is then used as the basis for a Simple Genetic Algorithm (SGA), which evolves 1 million individuals with simulated natural selection, crossover, and mutation. Running time is identical for both cases. The results of the two experimentsare compared, and the efficacy of the SGA on this problem is evaluated. The experiments were done at Sonoma State University and at CSU Sacramento by theauthor, with SSU Alumnus Terry Slocum.

Java: It's Better Than You Think, For Reasons You Haven't Realized You Already Know

William Grosso, Mountain View


In this talk, the speaker will draw upon his past experience as chair of SDForum's Java SIG ( and his current role as the chair of SD Forum's Emerging Technology SIG ( to explain why beginning and intermediate programmers should learn Java, why most (practical) software innovations over the next few years will involve programs written in Java, and why programmers using Java-based systems are going to reinvent the internet overthe next 5 years.

Luby-Rackoff Ciphers Over Finite Algebraic Structures Or Why Xor Is Not So Exclusive

Zully Ramzan, IP Dynamics, Campbell


Luby and Rackoff showed how to construct pseudo-random permutations from pseudo-random functions; their paper formalized the concept of a secure block cipher. Their goal was to understand what makes the U.S. Data Encryption Standard (DES) secure. The technique is based on composing several Feistel permutations. The Feistel permutation, a fundamental building block of DES, involves applying a so-called round function to the right half of the input and taking the XOR with the left half of theinput. We consider the question of what happens when operations other than the XORare applied. In particular, we engage in a study of Luby-Rackoff ciphers when the operation in the underlying Feistel network is addition over an arbitrary finite algebraic structure. We obtain the following results: We construct a Luby-Rackoff cipher which can be easily broken when XOR is used, but is secure against adaptive chosen plaintextand ciphertext attacks when addition in finite groups of characteristic greater than 2 are considered. This cipher has better time/space complexity and uses fewer random bits than all previously considered Luby-Rackoff ciphers. We show that our construction is tight when operations are performed over a finite field, and a minor relaxation in one ofthe requirements results in it being insecure, though the attack here is non-obvious. We examine various other Luby-Rackoff ciphers known to be insecure under XOR. In some cases, we can break these ciphers over arbitrary Abelian groups --- though we have to employ new more complex techniques. In other cases, however, the security remains an open problem. This talk is based on joint work with Sarvar Patel and Ganesh Sundaram of Lucent Technologies/Bell Labs, and appeared in SAC 2002.