> For the complete documentation index, see [llms.txt](https://documentation.astera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.astera.com/astera-data-stack-v10/workflows/file-transfer/sftp.md).

# SFTP

SFTP is a highly secure file transfer protocol that uses Secure Shell (SSH) to provide encryption and operates through a single port.

<figure><img src="/files/qqfXDSlCivV1wQU6ri6F" alt=""><figcaption></figcaption></figure>

*Private Key:* Uses a private key file for secure client authentication, pairing with a public key already configured on the server to ensure a highly secure, passwordless connection. Requires a file path to the private key file (e.g., .pem or .ppk) and an optional passphrase to decrypt the private key file if encrypted.

<figure><img src="/files/zU4yUjsHxjIg7oR5bio0" alt=""><figcaption></figcaption></figure>

*X.509 Certificate:* Uses an X.509 certificate for authentication, including the public key and metadata signed by a trusted certificate authority, often used in enterprise setups for added validation. Requires a file path to the certificate file (e.g., .crt or .cer) and a passphrase to access the certificate's private key securely.

<figure><img src="/files/AarGbOYHzpmdh8G8jkNM" alt=""><figcaption></figcaption></figure>


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