Abstract: An encryption and decryption system is provided. The system includes multiple sub-key tables, each sub-key table associated with an identifying number and multiple cipher engines arranged serially, each cipher engine capable of executing a different encryption operation on an input data stream using a sub-key table and producing an output data stream. The system also includes a number generator for generating numbers used to select sub-key tables. Data that assist deciphering engines with deciphering text encrypted with the cipher engines is inserted into the output data stream of at least one of the multiple cipher engines. The ciphering portion of the system also includes a checksum engine positioned prior to the last cipher engine and adapted to produce a checksum value for insertion into the input data stream of the last cipher engine.