On percolation and NP-hardness

On Percolation and NP-Hardness

We consider the robustness of computational hardness of problems whose input is obtained by applying independent random deletions to worst-case instances. For some classical NPhard problems on graphs, such as Coloring, Vertex-Cover, and Hamiltonicity, we examine the complexity of these problems when edges (or vertices) of an arbitrary graph are deleted independently with probability 1−p > 0. We...

On Basing Search SIVP on NP-Hardness

The possibility of basing cryptography on the minimal assumption NP * BPP is at the very heart of complexity-theoretic cryptography. The closest we have gotten so far is lattice-based cryptography whose average-case security is based on the worst-case hardness of approximate shortest vector problems on integer lattices. The state-of-the-art is the construction of a one-way function (and collisi...

On the NP-Hardness of Blocks World

Blocks world (cube world) has been one of the most popular model domains in artificial intelligence search and planning. The operation and effectiveness of alternative heuristic strategies, both basic and complex, can be observed easily in this domain. We show that finding an optimal solution is NP-hard in an important variant of the domain, and po cr ular extensions. This enlarges the range of...

Hardness Ampli ation Within NP

NP-Hardness of Cache Mapping

Plncessors sllch os the Iritel StrorigARM SA-1110 orid tlir Intel XScole provide ,fle.riDI~. contrnl oller tlie corhe riinnogen7ent to orhieve better roche z~tili:oriori. Pl-ogronis can specih tlie cache ~iinpying policy for each virtr~ol poge, i.e. niopping it to the mnirz cache, the riiini-coche, or neithel: For the latter cose, the pnge is mnrked ns nonr~cheoble. 111 tliis popel; we liiodel ...