The future of cryptography: practice and theory

Cryptography is one of the most active areas of research in computer science. It survives only where efforts to reduce computational complexity have failed, because the intractability of various problems keeps unwanted intruders at bay. Predicting its future, however, is difficult. Researchers are constantly devising new cryptosystems that are often based on new, untested intractability assumptions. For every cipher that a cryptanalyst breaks, two more seem to sprout up in its place. Despite the fact that revolutionary discoveries in algorithmics might render entire classes of cryptosystems obsolete overnight, the field likely will continue to survive due to its breadth and diversity alone.