The prevention of error propagation in dictionary compression with update and deletion

Abstract

In earlier work, we presented the k-error protocol, a technique for protecting a dynamic dictionary lossless data compression method from error propagation as a result of errors in the communication channel or compressed file. In the worst case, the protocol only protects against k errors in total; however, it gives a very high probability protection against a sustained error rate. Here, we further develop this protocol and present experiments showing that in practice this approach is both fast and highly effective against a noisy channel or faulty storage medium. We also address the issue of dynamically deleting strings. Although without modification most standard methods used in practice (e.g., LRU strategies) perform poorly with respect to error propagation, we propose and analyze some that are very robust, including a strategy based on leaf pruning.