This paper shows that Corollary 1 of “On Multiple Linear Approximations” is incorrect. In particular, the value given for the gain by Corollary 1 is likely to be a significant overestimate of this quantity. Thus, any data requirements for linear cryptanalysis with multiple linear approximations based on this value for the gain are highly questionable.

A theoretical framework for the use of multiple linear approximations in the linear cryptanalysis of block ciphers is given. The covariance of two mask counts is derived, and it is shown that under appropriate conditions the mask counts in linear cryptanalysis are stochastically independent, whether or not the masks are linearly independent. Some consequences of these observations are also considered

Media data delivery and processing such as telecommunications, networking, video processing, speech recognition and 3D graphics is increasing in importance and will soon dominate the processing cycles consumed in computer-based systems. This paper describes a processor called Linedancer, that provides high media performance with low energy consumption by integrating associative SIMD parallel processing with embedded microprocessor technology. The major innovations in the Linedancer is the integration of thousands of processing units in a single chip that are capable to support software programmable high-performance mathematical functions as well as abstract data processing. In addition to 4096 processing units, Linedancer integrates on a single chip a RISC controller that is an implementation of the SPARC architecture, 128 kbytes of data memory, and I/O interfaces. The SIMD processing in Linedancer implements the ASProCore architecture, which is a proprietary implementation of SIMD processing, operates at 266 MHz with program instructions issued by the RISC controller. The device also integrates a 64-bit synchronous main memory interface operating at 133 MHz (double-data rate, DDR), and a 64-bit 66 MHz PCI interface.