1. A cryptographic system, comprising: a data stream receiving device configured for receiving a modified data stream, said modified data stream comprising an input data stream representing a plurality of data entries encrypted using a chaotic sequence of digits; a user processing device configured for receiving user access information, said user access information specifying an initial value for said chaotic sequence of digits and data field location information associated with selected ones of said plurality of data entries; a chaotic sequence generator coupled to said user processing device, said chaotic sequence generator configured for generating one or more decryption sequences based on said initial value and said data field location information specified in said user access information; and a decrypter coupled to said chaotic sequence generator and said data stream receiving device, said decrypter configured for generating an output data stream from said modified data stream by applying said decryption sequences to said modified data stream.