File Watchdogs Home

Checking file integrity

File Watchdogs FTP Server includes support for file integrity checking. File integrity checking works by using an algorithm to calculate a unique number based on the contents of a file. When the same algorithm is run on the client computer before transferring the file and on the server computer after transferring the file, the results of the algorithm's computation can be compared to detect any corruption that may have occured during the transfer. If the transfer succeeded without corruption, the two values are identical.

The table below indicates the algorithms supported during FTP and SSH/SFTP connections as well as the command the client must issue to check the integrity of a file using one of the supported algorithms.

Algorithm	Client command	FTP	SSH/SFTP
SHA512	XSHA512
SHA256	XSHA256
SHA1	XSHA1
CRC32	XCRC
MD5	XMD5

An algorithm must be supported by both the server and the client to be used in file transfer checking. To determine which algorithms are supported by your file transfer client, consult its user documentation.