This is actually a Malayan Crested Porcupine Hystrix brachyura. The quills of this are distinctive (i.e. mostly white with a single black ring), and additionally the Sumatran Porcupine doesn't have a crest as is apparent on this animal.
@Chlidonias I have posted 2 photos of another animal that shared this same exhibit which should actually be Hystrix sumatrae. Let me know what you think, and possibly can add it to the Photographic guide!
