Altera Enigma is the Jazz fusion influenced Progressive metal/Rock band of Australian Jason De Ron (the former guitarist of Paramaecium), and Indonesian-Canadian Jefray Arwadi (guitarist and vocalist of Kekal). Both these musicians have a career that has seen them record and released nearly 20 albums between them.

Altera Enigma was formed as an outlet for Jason and Jeff to work together on music that would push their boundaries, challenge them musically and allow them to broaden their horizons and explore progressive music in all its forms. The addition of Kenny Cheong in 2005, a Jazz Fusion bassist who plays a five string fretless, allowed Altera Enigma to further develop their Jazz Fusion influences and develop their signature sound. They released their debut album, Alteration, in 2006.

2007 saw the addition of Jayson Sherlock( Mortification, Paramaecium, Horde) on drums.
While both Jason and Jeff may be more well known for their metal, with Paramaecium and Kekal having both released many albums of intense, evocative metal, actually both musicians are heavily influenced by Jazz and Progressive music in all its forms.

In early 2008 the members of Altera Enigma announced that they are making a new album but it is taking longer than initially expected as all the members of Altera Enigma are busy working with their primary bands. Jeff announced in 2010 that he has stepped down from the band, and his input for the new release will be minimal.