For over sixty million Americans, possessing a criminal record overshadows everything else about their public identity. A rap sheet, or even a court appearance or background report that reveals a run-in with the law, can have fateful consequences for a person’s interactions with just about everyone else. The Eternal Criminal Record makes transparent a pervasive system of police databases and identity screening that has become a routine feature of American life.

The United States is unique in making criminal information easy to obtain by employers, landlords, neighbors, even cyberstalkers. Its nationally integrated rap-sheet system is second to none as an effective law enforcement tool, but it has also facilitated the transfer of ever more sensitive information into the public domain. While there are good reasons for a person’s criminal past to be public knowledge, records of arrests that fail to result in convictions are of questionable benefit. Simply by placing someone under arrest, a police officer has the power to tag a person with a legal history that effectively incriminates him or her for life.

In James Jacobs’s view, law-abiding citizens have a right to know when individuals in their community or workplace represent a potential threat. But convicted persons have rights, too. Jacobs closely examines the problems created by erroneous record keeping, critiques the way the records of individuals who go years without a new conviction are expunged, and proposes strategies for eliminating discrimination based on criminal history, such as certifying the records of those who have demonstrated their rehabilitation.

Cryptology, the mathematical and technical science of ciphers and codes, and philology, the humanistic study of natural or human languages, are typically understood as separate domains of activity. But Brian Lennon contends that these two domains, both concerned with authentication of text, should be viewed as contiguous. He argues that computing’s humanistic applications are as historically important as its mathematical and technical ones. What is more, these humanistic uses, no less than cryptological ones, are marked and constrained by the priorities of security and military institutions devoted to fighting wars and decoding intelligence.

Lennon’s history encompasses the first documented techniques for the statistical analysis of text, early experiments in mechanized literary analysis, electromechanical and electronic code-breaking and machine translation, early literary data processing, the computational philology of late twentieth-century humanities computing, and early twenty-first-century digital humanities. Throughout, Passwords makes clear the continuity between cryptology and philology, showing how the same practices flourish in literary study and in conditions of war.

Lennon emphasizes the convergence of cryptology and philology in the modern digital password. Like philologists, hackers use computational methods to break open the secrets coded in text. One of their preferred tools is the dictionary, that preeminent product of the philologist’s scholarly labor, which supplies the raw material for computational processing of natural language. Thus does the historic overlap of cryptology and philology persist in an artifact of computing—passwords—that many of us use every day.