Network data files are secure through the operation of an infrastructure gateway-based network file access appliance. Network file data, corresponding to network pocket payload data, are further reduced to a sequence of data blocks that are secured through any combination of block encryption, compression, and digital signatures. File meta-data, including encryption, compression and block-level digital signatures are persistently stored with the file data, either in-band in the file as stored or out-of-band key as a separately stored file or file policy record. File meta-data is recovered with accesses of the file data to support bidirectional encryption and compression and to detect tampering with the file data by comparison against block-level digital signatures.