Decryption Failures in a Quantum World

The development of scalable quantum computers threatens the secrecy of communication by breaking classical encryption schemes. In order to ensure long-term security in communication networks quantum-safe cryptography is currently being developed and evaluated in standardization competitions.

A special property of many of the proposed cryptosystems is a low but non-zero probability of failure: An encrypted message may fail to decrypt successfully. This decryption depends on a secret key, which is to remain hidden to ensure secrecy of the communication. However, the mere event of such a failure has been shown to leak information about the secret key.

We analyze the vulnerability of quantum-safe cryptosystems to attacks based on these failures.
In particular, we construct a novel model of an adversary’s chance to trigger and exploit such failures on a quantum device.
As a result, new insights into protecting against quantum-attacks that enable the development of future quantum-safe encryption are collected.

Faculty Supervisor:

Michele Mosca

Student:

Partner:

Karlsruher Institut für Technologie

Discipline:

Computer science

Sector:

Education

University:

University of Waterloo

Program: