Speaking Stata: Matrices as Look-Up Tables

Speaking Stata: Problems with tables, Part I

Tables in some form or another are part and parcel of data management and analysis. The main general-purpose tabulation commands, tabulate, table, and tabstat, are reviewed and compared. When these do not provide a tabulation solution, one key strategy is to prepare the material for tabulation as a set of variables, after which the table itself can be presented with tabdisp or list. This is the...

Speaking Stata: Graphing distributions

Graphing univariate distributions is central to both statistical graphics, in general, and Stata’s graphics, in particular. Now that Stata 8 is out, a review of official and user-written commands is timely. The emphasis here is on going beyond what is obviously and readily available, with pointers to minor and major trickery and various user-written commands. For plotting histogram-like display...

Digital Look Up Tables and Real Number

Rijndael FPGA Implementations Utilising Look-Up Tables

This paper presents single-chip FPGA Rijndael algorithm implementations of the Advanced Encryption Standard (AES) algorithm, Rijndael. In particular, the designs utilise look-up tables to implement the entire Rijndael Round function. A comparison is provided between these designs and similar existing implementations. Hardware implementations of encryption algorithms prove much faster than equiv...

Higher Order Masking of Look-Up Tables

We describe a new algorithm for masking look-up tables of block-ciphers at any order, as a countermeasure against side-channel attacks. Our technique is a generalization of the classical randomized table countermeasure against first-order attacks. We prove the security of our new algorithm against t-th order attacks in the usual Ishai-Sahai-Wagner model from Crypto 2003; we also improve the bou...