On multiuser write-efficient memories

Continuing earlier work (Ahlswede and Zhang, 1989) on write-efficient memories (WEM), the authors introduce new models, where several persons use the same storage device. At any time instant, exactly one of a prescribed set of users has access to the memory, but there is no protocol which determines the moving order. Among the constraints analyzed, the most interesting one is a complete privacy protection. While a user stores new data, he has to guarantee that those of the others do not get distorted. This leads to fascinating new coding problems. The authors provide several code constructions, as well as abstract performance bounds. >