Trust but Check: Mutable Objects in Untrusted Cooperative Caches

Cooperative caching is known to be an effective technique for improving the performance of large scale distributed storage systems [5, 6, 7, 11, 1]. Nevertheless, current cooperative caching techniques work only in environments when machines trust one other, a requirement that is likely to become more and more difficult to satisfy. We describe a novel technique for managing cooperative caches in an untrusted environment. Our principal innovation is a new way to update objects on pages in untrusted caches while guaranteeing page integrity.