Abstract: In accordance with an example of an embodiment of the invention, a method for comparing a first unit of data stored in a first storage system and a second unit of data stored in a second storage system is provided. The method comprises generating a first digest that represents the first unit of data, generating an initial value associated with the first unit of data, and deriving an encoded value using the first digest and the initial value. The method further comprises transmitting the encoded value from the first storage system to the second storage system, generating a second digest that represents the second unit of data, and deriving a decoded value using the second digest to decode the encoded value. The method also comprises transmitting the decoded value from the second storage system to the first storage system, and determining whether the first unit of data and the second unit of data are duplicates of one another by comparing the decoded value and the initial value. Systems are also disclosed.

Abstract: In one embodiment, a method is provided for storing data in a physical storage having at least one portion of unused memory, comprising maintaining a first list comprising one or more records associated with respective segments within the unused memory, and receiving a request to store data in at least one logical storage sector associated with the physical storage. A record associated with a segment of the unused memory in which at least some of the data is to be stored is selected from the first list, and the record is updated to include an identifier of the at least one logical storage sector. The record is stored in a second list that associates respective segments with respective logical storage sectors.

Abstract: A method is provided to facilitate the detection of file tampering, such as a computer virus, on a computer. In one example, a digital fingerprint is generated for each file on the computer using a substantially collision-free algorithm. The digital fingerprints of the computer files are compared with digital fingerprints of the computer files generated when the files were previously saved. If the digital fingerprint of that file differs from the digital fingerprint generated when that file was previously saved, a computer virus or other tampering may exist on the file.

Abstract: A method is provided to audit license restrictions of a computer program in an enterprise computing environment. In one example, a digital fingerprint is generated of at least one file in the computer program using a substantially collision-free algorithm, and a digital fingerpring is generated for each file on each computer in the enterprise using the substantially collision-free algorithm. The digital fingerprints from the enterprise files are compared with the digital fingerprint of the computer program file, and the number of fingerprint matches is counted. Another method is provided for inventorying a computer program in an enterprise computing environment. In examples of both methods, a file may be divided into data blocks and a digital fingerprint may be generated for each data block.

Abstract: A method and system are provided for comparing data stored in a first storage system with corresponding data stored in a second storage system. In one implementation, the first system generates a random value associated with a respective data block P, and transmits to the second system an identifier associated with the data block P, and the random value. The second system generates a first digest representing a data block B, uses the first digest to encode the random value, producing a first encoded value, and transmits the first encoded value to the first system. The first system generates a second digest representing the data block P, uses the second digest to encode the random value, producing a second encoded value, and compares the first and second encoded values. If the two encoded values are equal, the data block B is a duplicate of the data block P. If the two encoded values are not the same, the data blocks are different.