Given that I have two pieces of data:
- A large piece of encrypted data.
- A small, fixed-size piece of random data.
I want to be able to transmit both pieces of data together, but I don't want the second piece of data to be readily available to a third party, but easily retrievable at the other end, assuming they know how it was hidden. It can't be encrypted as well.
For each message both pieces of data will be different.
Given the above, and assuming that an attacker has the knowledge that the payload they receive actually has both the above pieces of data is there any way to do some form of analysis to determine what the small piece of data is?