how to use salt to sign a message and how is it effective? I've had an assignment to sign a file using hash and salt, so I read about salt and I got why it's important when it comes to password, but not to sign messages.


How do I sign something using salt? The only way I could think of is that I add the salt to the message then hash both and then send the hash along with the salt (encrypted of course)… but it makes no sense to me.
Even if what I said earlier is how it's done, it's not useful at all. How and why would I use salt to sign a message ?
There are a couple of reasons why a salted signature would be helpful. It really depends on the particular implementation of a system.

For example if your message is encrypted, then signing with a salt could give you a different signature for the same message each time. This can be very important depending on the situation.

If the salt was actually provided by the client, then it could be used to prevent man-in-the-middle replay attacks. But there may be better ways to achieve this.