Abstract
Network decontamination (or disinfection) is a widely studied problem in distributed computing. Network sites are assumed to be contaminated (e.g., by a virus) and a team of agents is deployed to decontaminate the whole network. In the vast literature a variety of assumptions are made on the power of the agents, which can typically communicate, exchange information, remember the past, etc.
In this paper we consider the problem in a much weaker setting; in fact we wish to describe the global disinfection process by a set of cellular automata local rules without the use of active agents. We consider the grid, which is naturally described by a. 2-dimensional cellular automata, and we devise disinfection rules both in the common situation where after being disinfected a cell is prone to re-contamination by contact, and in a new setting where disinfection leaves the cells immune to recontamination for a. certain amount of time (temporal immunity). We also distinguish between Von Neuman and Moore neighborhood, showing that, not surprisingly, a bigger neighborhood allows for a more efficient disinfection.