2020/06/03 by Bart van der Vecht, Xavier Coiteux-Roy, van der Vecht, Bart +3
Computer Science · #Chaos-based Image/Signal Encryption #Cryptography and Data Security #FOS: Physical sciences #Quantum Physics (quant-ph) #User Authentication and Security Systems
paper · pdf · doi:10.48550/arxiv.2006.02476
openalex publication_date 2020/06/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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. Our scheme works if Alice is able to (reversibly) randomise the message to almost-uniformity with only a short key. By constructing an explicit attack we show that short-key unconditional tamper evidence cannot be achieved without this randomisability.