Hi Farhan,
Lets understand what's BLE and SFS.
Block-based encryption systems operate below the file system level, encrypting one disk block at a time. This is advantageous because they do not require knowledge of the file system that resides on top of them, and can even be used for swap partitions or applications that require access to raw partitions (such as database servers). Also, they do not reveal information about individual files (such as sizes and owners) or directory structure
Eg. BestCrypt (loopback driver)
Stackable file systems are a compromise between kernel-level disk-based file systems and loopback network file systems. Stackable file systems can operate on top of any file system; they do not have to copy data across the user-kernel boundary or through the network stack; and they are portable to several operating systems. Means metadata for each files hold on the header of the file. File got decrypted on another machine with the key from the linux keyring.
Eg.Cryptfs
Both are having its on advantages and disadvantages. Choose the best for your need. Look for throughput it supports and encryption it supported. Finally look for CPU overhead and IO penalities.
Hope I got answered your query.
Regards,
Sajan.S
