I have an application which consists of a client and a server. Both have a pair of public and private key (RSA). For communication, both sign their messages and send them to the other part. So a message Looks like this:
_____________________ | HTTP Post request | |___________________| | Post data | |___________________| | Signature | |___________________|
The post data is signed with the private key and the signature is added to the data. Sometimes the post data is very small (sometimes it just contains one number).
I know it can impact performance very much if I sign every little piece of data, but this time I'm not concerned too much about performance as the frequency of signing is very low.
Can it cause security problems if I sign very small amount of data such as just one number?