Adopting a digital signature standard.

Handwritten signatures on checks, contracts, and other paper forms have long served as a means of affirming that the contents of these documents are authentic. Last month, after nearly 3 years of debate, the National Institute of Standards and Technology in Gaithersburg, Md., announced the approval of the Digital Signature Standard (DSS), which performs a similar function for electronic messages and data (SN: 9/7/91, p.148).

The cryptographic technique underlying the signature standard generates a special number that allows users to verify both the integrity of the electronic information and the identity of the signer. However, though this method can be used to detect tampering and to prevent forgery of signatures, it does not encrypt the file or message itself.

The DSS makes use of a particular variant of a technique known as public-key cryptography. Such schemes require two mathematically related "keys" -- one for creating a digital signature as a scrambled string of bits and a complementary key for verifying the encoded signature.

The government insists that its version does not infringe on any of the patents on public-key cryptosystems held by various individuals and companies. It says it will not charge royalties to anyone using the standard. But several inventors have indicated they may sue the government for patent infringement.

Critics have also argued that the government standard is inefficient and may not be trustworthy. A number of computer companies have already adopted an alternative, competing public-key signature scheme for their products.