SFTP stands for SSH File Transfer Protocol and is a method of transferring files between machines over a secure, encrypted connection (as opposed to regular FTP, which functions over an insecure connection). The security in SFTP comes through its integration with SSH, which provides an encrypted transport layer over which the SFTP commands are executed. Net::SFTP::Foreign is a Perl client for the SFTP version 3 as defined in the SSH File Transfer Protocol IETF draft, which can be found at http://www.openssh.org/txt/draft-ietf-secsh-filexfer-02.txt This implementation uses an external OpenSSH-compatible program.