Suppose I need to store login information for a third-party website for a few users, how would I go about doing it?
Since I am logging into a third party website, I need the password in plain-text, not hashed. And no, the website in question does not provide any API.
In addition, the server I am using is accessible to people whose credentials are stored on it, so they will be able to get at least one plaintext/ciphertext pair, namely their own.
Given these two conditions, is there any way of storing user credentials on the server, or should I just ask for them each time the user logs in?