Jessica Fridrich (born Jiri Fridrich) is a Czech-American speedcuber who documented and popularised the CFOP method. Fridrich comes from Ostrava-Poruba, Czechoslovakia (now the Czech Republic). She is a professor in the Department of Electrical and Computer Engineering at the Binghamton University, USA.
Fascinated by puzzles and complex geometry, Fridrich even has Rubik's Cube inventor Ernő Rubik's signature in her notebook. Rubik signed the notebook at the Rubik's Cube World Championship in Budapest in 1982, an event where Fridrich finished tenth. In the Rubik's Cube World Championship in Toronto, Canada in 2003, she finished second. The CFOP method she popularised describes solving the cube in a layer-by-layer fashion. First, the"cross" is made on the first layer, consisting of the center piece and four edges. The first layer corners and edges of the second layer are put into their correct positions simultaneously (four pairs). The last layer is solved by first orienting and then permuting the last layer cubies using a large number of algorithms.
Fridrich first saw a Rubik's Cube at the age of 16 in March 1981. Cubes were not immediately available to buy in communist Czechoslovakia, but Fridrich was able to acquire a Cube in July from a visiting French family. After learning a Layer by layer technique from a Czech magazine, Fridrich was averaging around 1 minute by September. The national championship took place in May 1982 by which time Fridrich was averaging about 25 seconds. Fridrich was one of five cubers who advanced into the finals, among them, Mirek Goljan. Fridrich won the first and second rounds and Goljan won the last third round. The second round time of 23.55 seconds won Fridrich first place.
The First World Championship was held in Budapest, Hungary, on June 5. Fridrich, then 17, was representing Czechoslovakia, and finished in tenth place. Fridrich later stated that "I ended up in the exact middle with a baaad time 29.11." In Fridrich's opinion the championship had several severe flaws, most notably that "the cubes were really hard to turn and were not prepared for serious speed cubing". This meant that the cubes favoured competitors using systems with fewer moves. Fridrich was still using a "variant of the D, M, U layer method". Later that year Fridrich changed to a proper F2L method, and by 1983 was using about 120-150 algorithims and was consistently averaging 17 seconds.
In the 1990s Fridrich began working at SUNY Binghamton University in the USA, studying the subject of steganography and digital watermarking. (Mirek Goljan would later join Fridrich at SUNY Binghamton working in the same field.) Fridrich put the CFOP system on the Internet in January 1997, apparently believing "that speedcubing was inactive and not popular enough for anybody to have the motivation to go through the pain of memorizing the algorithms".
Fridrich was actively involved in the revival of speedcubing (for example meeting and encouraging a fresh-faced Dan Knights in the summer of 1999). Now known as Jessica, she attended Dutch Cube Day in 2002: "for me, it was the biggest concentration of cube-crazy minds since the World Championship in 1982". She entered the 2nd World Championship in August 2003 at the Ontario Science Center in Toronto. She finished in 2nd place (behind 1st-placed Dan Knights) with a best time of 17.12 seconds. She subsequently competed in the Caltech Winter 2005 and Cornell Spring 2007 competitions.