Your retailer login credentials (Amazon, B&N, Apple, etc.) are encrypted using AES-256 and stored in a keystore on your computer. When Publishwide needs to authenticate with these retailers, it will use the keystore on your computer to directly interface with each retailer's authentication servers.
Publishwide does not keep your login credentials anywhere on our servers, and your login information will never leave your computer.
The only ways that your passwords could be compromised are:
Malicious actors gain access to your computer
You're using the same passwords as other accounts that have been compromised.