# Secure file transmission

> Learn about the security requirements to ensure secure file transmission.

Fulfill these security requirements to ensure secure file transmission.

# SFTP account management 

If the SFTP server of Antom is used, contact technical support to obtain the credentials to log in to the SFTP server. 

If the SFTP server of a partner is used, partners must complete the SFTP server system configuration on Antom first. 

# File transfer process 

File exchange happens between Antom and partners. 

For the file sender, the file uploading process is as follows:

![image.png](https://idocs-assets.marmot-cloud.com/storage/idocs87c36dc8dac653c1/1592968688402-1ec1a500-5e3b-4b6f-a4be-4e54787209f9.png)

Figure 1. File uploading process

For the file receiver, the file downloading process is as follows: 

![image.png](https://idocs-assets.marmot-cloud.com/storage/idocs87c36dc8dac653c1/1592968688878-c4c8296e-36f9-4ae3-a751-19305faa92ee.png)

Figure 2. File downloading process 

## Pre-upload process 

Before the transmission, encrypt files by using the PGP algorithm to enhance transmission security. A .asc suffix is added to the encrypted file to differentiate it from the unencrypted file. 

## Upload files 

To prevent temporary files from being wrongly downloaded, rename the file by appending a .tmp suffix to the file name before uploading. After the transmission is completed, rename the file back to the original name by removing the .tmp suffix. 

## Download files 

Do not download the temporary file, which has a .tmp suffix. 

After the file is downloaded, decrypt the file by using the PGP algorithm. 

## File retention 

Files on the SFTP server can be kept for seven days. Files older than seven days are automatically removed from the server.