Study of the impact of security on performance in PC clusters.

Summary Developed since the beginning of the 90s, PC clusters are increasingly becoming an alternative to supercomputers. In particular, the recent advent of gigabit networks has reinforced this position. It is in this context that the multi-PC machine was developed, implementing the remote write protocol (where the local and remote physical addresses must be specified by the message sender). If this protocol is very efficient, the use of physical addresses by the user constitutes a very important security hole. The organization of contiguous physical memory blocks͏̈, The protection of these blocks through a signature and/or an encryption, original efficient mechanisms adapted to this information, the fine evaluation of the various times intervening in the transmissions are the main contributions of this thesis.