Transferring files over SFTP is safe and secure, but does come with certain security requirements you should keep in mind.

When transferring files to or from Sendle via SFTP, you'll need to make sure your software is using the ciphers and cryptographic algorithms listed on this AWS Transfer page. Because our SFTP endpoints are a fully managed service, we have limited control over which key exchange algorithms are allowed – though we try our best to be lenient (we're currently using TransferSecurityPolicy-2018-11).

If your software only supports ciphers or algorithms that are not on the above list (for example, older ciphers or algorithms), connections may stop working without warning. If your software complies with the latest policy listed on that page, it should continue working for a long time to come.