Two new subject bibliographies have recently been published by the Library's Science and Technology Division in its "Tracer Bullet" series.
The first, Cryptology, concerns the making and breaking of codes and ciphers. Cryptography is that part of cryptology concerned with conveying messages in a secret or encrypted form, and cryptanalysis is the reading of encrypted messages without having authorized knowledge of the key that was used in encryption.
With advances in computers and telecommunications, and increased dependence on such systems, the use of cryptography has found new applications in the lives of individuals and in the world of commerce. Cryptography has proved to be the best technique for protecting information transmitted through accessible communications networks such as telephone lines, satellites and microwave systems.
Cryptology was once the domain of the government, especially for military and diplomatic purposes, but it is increasingly becoming a mathematical discipline, as mathematics provides the theoretical justification behind the strength of a particular encryption system. While this makes possible much more interesting, complicated and sophisticated encryption systems, it also means that a degree of mathematical expertise is required.
Another bibliography, Biodiversity, replaces an earlier edition with the same title. Biodiversity, or biological diversity, is usually defined as the variety and variability of living organisms and the biological communities in which they live, plus the ecological and evolutionary processes that keep them functioning. Biodiversity is directly and indirectly affected by human activities, which sometimes lead to reductions in diversity; an example is the destruction of habitats. Some scientists and environmentalists think the loss of diversity should already be considered a crisis and will accelerate in the near future. They argue that biodiversity must be maintained because of the ecosystem services, economic benefits and evolutionary potential it provides, as well as for aesthetic and ethical reasons.
These guides are not intended to be comprehensive bibliographies. Based on holdings of the Library of Congress, Tracer Bullets are designed -- as the name of the series implies -- to put the reader "on target." To facilitate further research, LC subject headings are included, under which additional resources can be located in most card, book and online catalogs.
Tracer Bullets, which are free of charge, may be obtained by writing to the Science and Technology Division, Library of Congress, Washington, DC 20540, or by telephoning (202) 707-5664. If a recording is heard, which occasionally happens, leave your name, address and request. A list is available of many other Tracer Bullets on timely subjects in science and technology.
For those with Internet access, all Tracer Bullets from 1989 to the present, as well as selected older Tracer Bullets, can be read on SCTB Online. Currently, Cryptology is featured on the "What's New" page of the site. Biodiversity will soon be uploaded. The SCTB Online file can be reached directly or from the Science Reading Room home page.