US Patent 8082231 Techniques using identifiers and signatures with data operations

Described are techniques for representing a data segment comprising. A list of one or more tokens representing one or more data portions included in the data segment is received. A unique identifier uniquely identifying said data segment from other data segments is received. A signature value determined in accordance with said list of tokens and said unique identifier is received. The list of tokens, said unique identifier, and said signature value are stored as information corresponding to said data segment.