The File Transfer Protocol (FTP) is a standard network protocol used for the transfer of computer files between a client and server on a computer network. dCache supports varous extensions allow you to list files with FTP and manage them.
The GridFTP protocol extensions support a number of advanced features. On of these features is to protect the control channel and allow the client to negotiate a secure data channel, as described in RFC 2228.
dCache supports GridFTP with a secure control channel, but does not support a secure data channel: all data is transferred unencrypted.
globus-url-copycommand supports the options
-data-channel-private) that the man page describe as:
Set data channel protection mode to PRIVATE
There is a bug where a transfer with the
-data-channel-private) option specified will succeed with dCache, but the file’s contents is sent unencrypted over the network.
Therefore we recommend that you NEVER use the
-data-channel-privateoption as it’s behaviour is unreliable.