Curtin tells the story of the achievement of thousands of volunteers, who in 1997 were able to show that the data encryption standard (DES) was too weak as a cryptographic algorithm. Their effort was in response to a January 1997 contest initiated by RSA Data Security that challenged DES. In this contest, RSA provided a message that was encrypted using DES with a 56-bit key, and promised $10,000 to anyone who could decrypt the message or break the code that hid it.

The winning attempt was conducted by a group of programmers, computer scientists, and technology enthusiasts that called themselves DESCHALL. This loosely connected team used tens of thousands of computers across the United States and Canada in a distributed supercomputing effort. Machines were connected to a key server that provided them individually with sets of unique keys in an attempt to simply try all possible (roughly 72 quadrillion) decryption keys until the right one was found. The author was a leading member of DESCHALL, and, as such, provides many details about the challenges faced and the steps taken to overcome these challenges.

The book begins with an easy-to-understand, brief introduction to cryptography intended for the nonspecialist. This is followed by some background information about the author. The rest of the book consists of a detailed chronology of the events in early 1997 that led the group to success in their code-breaking effort. Although of general interest as an important development in the history of cryptography, the narrative, in places, is tedious and outright boring. The author, who is obviously excited about and proud of the success of the project, presents the daily obstacles that needed to be overcome. He mentions many different people and their contributions. Unless a reader is planning to undertake a similar distributed computing endeavor, however, these details become overwhelming after awhile, and led me to lose interest. Curtin also never misses a chance to celebrate his own contributions, which I found to be somewhat irritating.

The main flaw of the book is that the author, when writing it, didn’t seem to have a clear audience in mind. His mentioning of all the names and personal stories led me to believe that it was written for the people who enabled the success of the DESCHALL project. It immortalizes their contributions. On the other hand, the book does not make any assumptions about any knowledge of cryptography. To illustrate the scope of the task, the author repeatedly tries to impress readers who are not familiar with cryptography with large numbers, which annoyed me. Moreover, when faced with the long list of repetitive stories about challenges that needed to be overcome, I suspect that many readers will quickly lose whatever interest in the subject they might have had. So, ultimately, the people who will enjoy this book the most are readers that were involved in DESCHALL or readers who are planning their own distributed supercomputing efforts. For such readers, I can fully recommend this book.