Lawrence E. Bassham

Report on the Development of the Advanced Encryption Standard (AES)

In 1997, the National Institute of Standards and Technology (NIST) initiated a process to select a symmetric-key encryption algorithm to be used to protect sensitive (unclassified) Federal information in furtherance of NIST’s statutory responsibilities. In 1998, NIST announced the acceptance of 15 candidate algorithms and requested the assistance of the cryptographic research community in analyzing the candidates. This analysis included an initial examination of the security and efficiency characteristics for each algorithm. NIST reviewed the results of this preliminary research and selected MARS, RC™, Rijndael, Serpent and Twofish as finalists. Having reviewed further public analysis of the finalists, NIST has decided to propose Rijndael as the Advanced Encryption Standard (AES). The research results and rationale for this selection are documented in this report.

Expert assistance for manipulating of SGML document type definitions

The DTD editing tool is a window and icon based tool for creation, manipulation and comprehension of SGML Document Type Definitions (DTDs). This tool allows users to manipulate SGML DTDs without any knowledge of the rather complex SGML syntax. More generally, the tool allows users to manipulate context-free grammars without any knowledge of the syntax used to describe them. The tool generates SGML DTDs, and has features specific to that application; however, the approach could also be applied to the manipulation of context-free grammars represented in other grammar description languages.