Jan Sloot

The Sloot Digital Coding System (SDCS) is an alleged technique for data encoding claimed to have been invented in 1995 by Romke Jan Bernhard Sloot (1944–1999), an electronics engineer in the Netherlands. Sloot claimed his system could represent an entire feature film with only one kilobyte of data, a level of compression which is mathematically impossible according to Shannon's source coding theorem.

Sloot demonstrated the technology by recording and playing back video, apparently using a small smart card which stored a unique identifier by which any possible video could be referenced. He convinced entrepreneurs Roel Pieper, Marcel Boekhoorn, and Tom Perkins to invest in the technology. However, several days before the conclusion of a contract to sell his invention, Sloot died of a sudden heart attack, and his source code was lost forever. His claims have never been reproduced or verified. Contrary to his claims, the playback device he used was discovered to contain a hard drive.

Software engineer Adam Gordon Bell speculated that Sloot had come upon a variation of shared dictionary compression, a known technique. He speculates that Sloot believed in his idea because he failed to understand its mathematical limitations, and faked the demonstrations in order to buy time while refining the details.

Background Sloot was born in Groningen on 27 August 1944, the youngest of three children. His father, a school headmaster, left his family quite soon after Sloot's birth. After fulfilling mandatory military service, Sloot settled in Utrecht with his wife. , just the plain text alone of the Dutch Wikipedia page describing the film Casablanca occupies 29 kilobytes.

Roel Pieper, former CTO and board member of Philips, is quoted as saying (translated from Dutch):

It is not about compression. Everyone is mistaken about that. The principle can be compared with a concept as Adobe-postscript, where sender and receiver know what kind of data recipes can be transferred, without the data itself actually being sent.

After his death, a software engineer Sloot had worked with analysed Sloot's demonstrations. Despite Sloot's claim that his coding system stored all of its data on smart cards, his demonstration device was found to contain a hard disk. Bell says that Sloot seems to have believed that he had created a novel encryption technology, but posthumous analysis suggests that he had actually created a variation of shared dictionary compression, a known data compression technique with predictable and finite mathematical limitations. Bell speculates that Sloot thought he could overcome these limitations with better coding, and faked the demonstrations to buy time to improve the code, but that the inherent mathematical limitations of the coding system would have inevitably proven impossible to overcome.