Security is becoming an increasingly more important concern both at the desktop level and at the network level. This article discusses several approaches to authenticating individuals through the use of biometric devices. While libraries might not implement such devices, they may appear in the near future of desktop computing, particularly for access to institutional computers or for access to sensitive information. Other approaches to computer security focus on protecting the contents of electronic transmissions and verification of individual users. After a brief overview of encryption technologies, the article examines public-key cryptography which is getting a lot of attention in the business world in what is called public key infrastructure. It also examines other efforts, such as IBM’s Cryptolope, the Secure Sockets Layer of Web browsers, and Digital Certificates and Signatures. Secure electronic transmissions are an important condition for conducting business on the Net. These business transactions are not limited to purchase orders, invoices, and contracts. This could become an important tool for information vendors and publishers to control access to the electronic resources they license. As license negotiators and contract administrators, librarians need to be aware of what is happening in these new technologies and the impact that will have on their operations.