Definition - What does Secure Copy mean?
Secure copy (SCP) is a file transfer protocol, which helps in transferring computer files securely from a local host to a remote host. It works on the Secure Shell (SSH) protocol technique.
The term secure copy refers to either the SCP protocol or the SCP program. The SCP protocol is a file transfer network protocol, which supports encryption and authentication features. It is based on the Berkeley Software Distribution (BSD) Remote Copy Protocol (RCP), which runs on port 22 using the SSH Protocol.
Techopedia explains Secure Copy
SCP can be called more of a combination of RCP and SSH than a protocol because the file transfer is performed using RCP and authentication and encryption are provided by the SSH Protocol. SCP maintains the confidentiality of the data being transferred and protects the authenticity by blocking packet sniffers from extracting valuable information from the data packets.
The SSH protocol supports the inclusion of basic attributes like permissions and timestamps for the file to be uploaded. The inclusion of a date/timestamp attribute is not supported in common FTP. The client provides the server with all the files to be uploaded. A request for downloading the files and directories is sent by the client. The server provides the client with all the subdirectories and files available for download. Since the download is controlled by the server, there are chances of security risks when connected to a malicious server.
On the other hand, the SCP program implements the SCP protocol as a client or a service daemon. The SCP server program and the SCP client are one and the same. A typical example of an SCP program is the command line SCP program available with most of the SSH implementations.