Abstract: Multi-level file digests for electronic files are disclosed. A top level digest represents a single digest for the associated electronic file. Lower level digests represent digests for portions of the associated electronic file. The top level digest is derived from the lower level digests. The top level digest is useful for facilitating rapid comparison to determine whether electronic files are the same. In one embodiment, electronic files are encrypted with a block encryption scheme, and digests are efficiently calculated and stored on a block-by-block basis. Advantageously, when modifications to an encrypted electronic file occurs, only those modified blocks need to be processed to undergo decryption and re-encryption to determine the appropriate digest.

Abstract: Multi-level file digests for electronic files are disclosed. A top level digest represents a single digest for the associated electronic file. Lower level digests represent digests for portions of the associated electronic file. The top level digest is derived from the lower level digests. The top level digest is useful for facilitating rapid comparison to determine whether electronic files are the same. In one embodiment, electronic files are encrypted with a block encryption scheme, and digests are efficiently calculated and stored on a block-by-block basis. Advantageously, when modifications to an encrypted electronic file occurs, only those modified blocks need to be processed to undergo decryption and re-encryption to determine the appropriate digest.

Abstract: Techniques for utilizing security criteria to implement document retention for electronic documents are disclosed. The security criteria can also limit when, how and where access to the electronic documents is permitted. The security criteria can pertain to keys (or ciphers) used to secure (e.g., encrypt) electronic files (namely, electronic documents), or to unsecure (e.g., decrypt) electronic files already secured. At least a portion of the security criteria can be used to implement document retention, namely, a document retention policy. After a secured electronic document has been retained for the duration of the document retention policy, the associated security criteria becomes no longer available, thus preventing subsequent access to the secured electronic document. In other words, access restrictions on electronic documents can be used to prevent access to electronic documents which are no longer to be retained.

Abstract: Multi-level file digests for electronic files are disclosed. A top level digest represents a single digest for the associated electronic file. Lower level digests represent digests for portions of the associated electronic file. The top level digest is derived from the lower level digests. The top level digest is useful for facilitating rapid comparison to determine whether electronic files are the same. In one embodiment, electronic files are encrypted with a block encryption scheme, and digests are efficiently calculated and stored on a block-by-block basis. Advantageously, when modifications to an encrypted electronic file occurs, only those modified blocks need to be processed to undergo decryption and re-encryption to determine the appropriate digest.

Abstract: Improved techniques for transferring files through a multi-tier computing environment are disclosed. The transfer of files across the multiple tiers of the computing environment can use staging at intermediate tiers to facilitate the file transfer. Each tier can include at least one computing machine that includes a file transfer manager. The file transfer managers at the computing machines in each of the multiple tiers serve to effectuate the file transfer through the multi-tier computing environment. In one embodiment, the multi-tier computing environment is a multi-tier file security system and the files being transferred are audit files.