Can't Touch This: unconditional tamper evidence from short keys

Understand

Storing data on an external server with information-theoretic security, while using a key shorter than the data itself, is impossible.

• As an alternative, we propose a scheme that achieves information-theoretically secure tamper evidence: The server is able to obtain information about the stored data, but not while staying undetected.
• Moreover, the client only needs to remember a key whose length is much shorter than the data.
• We provide a security proof for our scheme, based on an entropic uncertainty relation, similar to QKD proofs.