Abstract: An information processing system providing archive/backup support with privacy assurances by encrypting data stored thereby. Data generated on a source system is encrypted, the key used thereby is separately encrypted, and both the encrypted data and encrypted key are transmitted to and maintained by a data repository system. The repository system receives only the encrypted data and key, while the source system retains the ability to recover the key and in turn, the data. The source system is therefore assured of privacy and integrity of the archived data by retaining access control yet is relieved of the physical management of the warehousing medium.

Abstract: A method for the administration of a differential file backup system in a client-server system is disclosed in which the various component files that comprise a backup file are read from a first memory device of the file backup system to a second memory device and processed by the server. The server processes the various file components, or archive files in which the various file components reside, to reduce the number of access points across the first memory device to enhance the efficiency of the file retrieval, file reconstruction, and file restore operations of the backup file system.

Abstract: A method and apparatus for providing a multiple copy file backup system is disclosed in which files that have been previously backed up by a first user are to be backed up by different users. The first instance of backing up a file results in storing the file in a first location and associating the file and user in an entry in 238808-1a file data table. For other users needing to backup the same file, the contents of the file are copied from the first location into a second location within the file backup storage system. The file backup system creates two new entries in the file data table. In one entry the file stored in the second location is associated with a User-Pool that allows sharing the file contents among the users. The second and subsequent entries in the file data table will be created as subsequent users desiring desire to backup the file.

Abstract: A method for the administration of a differential file backup system in a client-server system is disclosed in which the various component files that comprise a backup file are read from a first memory device of the file backup system to a second memory device and processed by the server. The server processes the various file components, or archive files in which the various file components reside, to reduce the number of access points across the first memory device to enhance the efficiency of the file retrieval, file reconstruction, and file restore operations of the backup file system.

Abstract: A database of known commercial software programs ("Products") is maintained and employed as a template for selection of files for a backup operation. In particular, files which are part of known Products may be excluded during backup operations. Records indicating rules about which files within Product directories are included and excluded from the backup operation are also maintained in the database. Product directories may be determined from a registry or the hard disk may be scanned and directories checked against a list of known Product default directories. If the newly found directory does not match an entry in the list of default directories, then file list codes in the database are checked against the files in the directory to determine whether known Product files are present in the directory. Two types of exclusion commands are employed to identify files for exclusion from the backup operation by exploiting file creation and modification dates.

Abstract: File comparison employs a single function F to calculate a digital signature from data in a sliding window. The digital signature is both incrementally computable and position sensitive. In particular, F is computable without reprocessing each byte in the array when the window is advanced and facilitates detection of such changes as transposed bytes of data. The function F is defined by two qualities. First, for F(A+B), where A is an array, F(A+B)=F(A)+F(B). Second, given a concatenation operator "!" such that "0!A" indicates an array A with 0 inserted before A, the function F has the property that there is a function G such that F(0!A)=G(F(A'0)). Both polynomials and cyclic redundancy checks ("CRC") may be used as that class of function.

Abstract: A information processing system providing archive/backup support with privacy assurances by encrypting data stored thereby. Data generated on a source system is encrypted, the key used thereby is separately encrypted, and both the encrypted data and encrypted key are transmitted to and maintained by a data repository system. The repository system receives only the encrypted data and key, while the source system retains the ability to recover the key and in turn, the data. The source system is therefore assured of privacy and integrity of the archived data by retaining access control yet is relieved of the physical management of the warehousing medium.