This paper presents the substitution boxes (s-boxes) found in many block ciphers, and more specifically in DES-like encryption systems. It begins with a brief history of the Data Encryption Standard (DES) and the first public question on the chosen s-boxes. An outline of the DES algorithm is presented, along with a more detailed look of the cipher function that uses the s-boxes. The major metho...

This paper presents the substitution boxes (s-boxes) found in many block ciphers, and more specifically in DES-like encryption systems. It begins with a brief history of the Data Encryption Standard (DES) and the first public question on the chosen s-boxes. An outline of the DES algorithm is presented, along with a more detailed look of the cipher function that uses the s-boxes. The major metho...

Let T be a protoset of d-dimensional polyominoes. Which boxes (rectangular parallelepipeds) can be tiled by T ? A nice result of Klarner and Göbel asserts that the answer to this question can always be given in a particularly simple form, namely, by giving a finite list of “prime” boxes. All other boxes that can be tiled can be deduced from these prime boxes. We give a new, simpler proof of thi...

This paper presents the substitution boxes (s-boxes) found in many block ciphers, and more specifically in DES-like encryption systems. It begins with a brief history of the Data Encryption Standard (DES) and the first public question on the chosen s-boxes. An outline of the DES algorithm is presented, along with a more detailed look of the cipher function that uses the s-boxes. The major metho...

We present preliminary results on dynamic self-adaptation of streaming networks of concurrent programs (called boxes) to the underlying hardware platform. The monitoring subsystem gathers on-line measurements on the performance of individual boxes and uses the measurements to construct (and improve) performance models of the boxes. Ideally, the models accurately predict the running time of boxe...

Many proteins consist of subdomains that can fold and function independently. We investigate here the interaction between the two high mobility group (HMG) box subdomains of the nuclear protein rHMG1. An HMG box is a conserved amino acid sequence of approximately 80 amino acids rich in basic, aromatic and proline side chains that is active in binding DNA in a sequence or structure-specific mann...

We discuss rectangle and box visibility representations of graphs in 3-dimensional space. In these representations, vertices are represented by axis-aligned disjoint rectangles or boxes. Two vertices are adjacent if and only if their corresponding boxes see each other along a small axis-parallel cylinder. We concentrate on lower and upper bounds for the size of the largest complete graph that c...

Measuring cups are everyday instruments used to measure the amount of liquid required for many common household tasks such as cooking. A measuring cup usually has gradations marked on its sides. In this paper we study measuring boxes without gradations which can nevertheless measure any integral amount, say liters, of liquid up to their full capacity. These boxes will be called universal measur...

Recently, Courtois and Pieprzyk proposed an attack on symmetric ciphers that takes advantage of a previously-unexploited property of substitution boxes, or s-boxes, in the round function. This paper gives a brief overview of this “overdefined system of equations” attack and shows how the attack may be avoided through the use of round functions that contain a variety of protection mechanisms, in...