[jupiter909]

Thought they used Parsons Code as it is space efficient as a fingerprinting technique and less across the wire too for a partial fingerprint and it handles tempo drift. In addition I know they where becoming CPU bound and then moved to GPU to do matching, that greatly helped them.

[mgachka]

When I started this side project in 2012, I looked for publicly reliable information (especially thesis or research papers) and the only useful information I found was Shazam confounder’s paper.

Since this paper was written in 2003, I wouldn't be surprised if they have changed their algorithms since this time.

But from my understanding, the 2003 paper describes a highly scalable architecture and a noise tolerant and "time efficient" algorithm (that can be modified using thresholds) so it could still work in 2015 with a few optimizations. Still, I'm not working at Shazam and I'm not a researcher so I could be wrong.