Home » Science » Computer Science » What is the Knuth Reward Check?

What is the Knuth Reward Check?

Donald Knuth, the Father of Analysis of Algorithms, is the author of The Art of Computer Programming. This book is considered the bible of modern-day Computer Science.

Donald Knuth created a reward system for finding errors in his book. He sends checks for $2.56 for each mistake found and has sent over 2,000 checks valued at $20,000. Most of the checks weren’t cashed. Instead, it was kept and framed for bragging rights.

Donald Knuth was born in Milwaukee, Wisconsin. He was born just a year before the dreaded World War 2 took place on January 10, 1938. At a young age, Knuth has already shown superior intelligence. He joined a contest and won a television set and a lot of candy bars for his school. (Source: Computer History)

Who is Donald Knuth?

Knuth received a scholarship in physics and continued earning his Ph.D. in Mathematics, showcasing his extraordinary mind. In the years that followed, he published many books relating to Computer Science. In the 70s, the field of Computer Science was new. Knuth saw this field as having no real identity, no standards, and very few available references. (Source: BBVA Foundation)

He began writing his book, The Art of Computer Programming. The book is, to date, still unfinished. The book consists of seven volumes, to be exact. The book has seen numerous edits and changes, adapting to Computer Science’s nature – continuously evolving. Knuth also authored numerous books, all contributing to the field. (source: TAOCP)

What is the Knuth Reward Check?

Knuth designed the Knuth Reward Check as an easter egg reward system for those who find flaws in his publications. It can come in the form of a simple typographical error to more technical or historical errors. It can also be in the form of substantial suggestions to his publications.

He began this easter egg hunt in 1995, sending out $2.56 to the first person to find errors in his books. The amount of $2.56, corresponds to 1 hexadecimal dollar. (Source: Stanford Faculty)


As of October 2001, Knuth has written more than 2,000 checks, each check valued at $8. Most often, awardees did not cash these checks. They have been kept as memorabilia, or put, a bragging right, for having found an error in his works. (Source: NPR)

What is the Bank of San Serriffe?

In 2008, Knuth stopped sending actual checks to his easter egg awardees. The decision came when his bank advised him of the new trends in check fraud. It was simply too easy to gain information and steal money off a written check.

To continue rewarding individuals that help him perfect his publications, Knuth came up with the fictitious Bank of San Serriffe. He then writes personal certificates of deposit for each awardee. Awardees still receive the bragging rights check from Donald Knuth via the Bank of San Serriffe.

Awardees can find their balances on the Bank of San Serriffe website.

The bank is purely whimsical, something out of Knuth’s imagination. Its address is Thirty Point, Caissa Inferiore, San Serriffe, Pincus. Many speculate that these places are from random fictitious stories that Knuth may have encountered in his years.

Regardless of the fact, easter egg hunters are still active up to this day, still working their way to have their account in this fictitious bank. This alone still proves Knuth’s intelligence and worth in earning his title as the “Father of Analysis of Algorithms”. (Source: Stanford Faculty)

Leave a Comment

%d bloggers like this: