Sending Payment Files with an SSH Key vs PGP Encryption

Summary:

Hello -

At my current client, there is desire to send payment files upon completion to the respective banking partner. The bank requires an SSH Key exchange. We have been able to generate a public SSH Key that allows for pairing with the bank. Where can I upload the public SSH key to sign the payment file and utilize the credentials provided by the bank, to access the bank's server?

I am familiar with the PGP key encryption techniques and what is available in Fusion. Please gear responses specifically to SSH Keys, and how you have been able to achieve sending payment files with an SSH key vs PGP.