1. A system for compressing data by reducing the number of binary bits required to represent the data comprising: memory means for storing each of a plurality of selected units of a set of units in unit positions to form a library, each unit position having a memory address expressed in bits, processing means for detecting each unit in the data and searching the memory to determine if the respective unit in the data is in the library, and alternatively compiling data representative of the units which are not stored in the memory library or the addresses of the units which are stored in the memory library together with a code indicating which alternative is compiled in each instance.
1. A system for compressing data by reducing the number of binary bits required to represent the data comprising: memory means for storing each of a plurality of selected units of a set of units in unit positions to form a library, each unit position having a memory address expressed in bits, processing means for detecting each unit in the data and searching the memory to determine if the respective unit in the data is in the library, and alternatively compiling data representative of the units which are not stored in the memory library or the addresses of the units which are stored in the memory library together with a code indicating which alternative is compiled in each instance. 9. The system of claim 1 further comprising means coupled to the processing means for encrypting the compressed data stream.