Why Quantum Computing Will Not Destabilize International Security: The Political Logic of Cryptology

Abstract

The implications of quantum information technology for cybersecurity and strategic stability seem worrisome. In theory, an adversary with a quantum computer could defeat the asymmetric encryption protocols that underwrite internet security, while an adversary using quantum communications guaranteed secure by the laws of physics could deny intelligence warning of surprise attack. To assess these claims, this article first develops a general political logic of cryptology grounded in the bargaining model of war, which understands uncertainty as an important cause of war and institutions as an important source of information. Cryptology of any technological vintage is shaped by both aspects of this logic, with ambiguous implications for strategic stability. In practice, strategic interaction between intelligence competitors using real quantum systems implemented in fallible human organizations will mitigate the impact of quantum computing. The upshot is that the revolutionary scientific innovation of quantum computing will probably have only marginal political impact, in part because the fields of cryptology and computing have already undergone important transformations in recent decades.