What question did this study set out to answer?

The aim is to develop a framework for enterprises to transition to post-quantum cryptographic standards and assess associated risks.

April 4, 2026Open Access

Post-quantum readiness and cryptographic transition planning for enterprise cloud

Key Points

The aim is to develop a framework for enterprises to transition to post-quantum cryptographic standards and assess associated risks.
Developed a standards-based algorithm selection framework using NIST's post-quantum standards.
Created a cloud threat model to identify risks including retroactive confidentiality loss.
Utilized a quantitative timing-risk model grounded in Mosca’s inequality.
Applied a Monte Carlo estimator for comparison of migration strategies.
Delaying migration start by four years increases expected exposed fraction of confidentiality window from 0.37 to 0.54.
Probabilistic estimates showed significant sensitivity to tail uncertainty compared to deterministic planning.

Abstract

Abstract Cryptographically relevant quantum computers (CRQCs) would break widely deployed public-key cryptography (RSA/ECC) via Shor’s algorithm, enabling retroactive decryption of captured ciphertext (“harvest now, decrypt later”). This paper presents an enterprise-cloud transition framework that couples (i) standards-based algorithm selection using NIST’s post-quantum standards (FIPS 203–205), (ii) a cloud threat model that distinguishes retroactive confidentiality loss from forward integrity/authentication risks, and (iii) a quantitative timing-risk model grounded in Mosca’s inequality. Using a public expert-elicitation distribution for Q-day timing and a reproducible Monte Carlo estimator, we compare migration strategies and key planning parameters (migration start year, migration duration, and confidentiality lifetime). We also contrast this probabilistic view with common deterministic single-date Q-day planning, highlighting how tail uncertainty can materially change exposure estimates and recommended start years. For a representative enterprise case (X=10 X = 10 years, Y=6 Y = 6 years), delaying the migration start from 2026 to 2030 increases the expected exposed fraction of the confidentiality window from 0. 37 to 0. 54 under a midline timeline. We also provide cloud-specific implementation guidance (crypto inventory, hybrid TLS/QUIC and service-mesh deployments, PKI readiness, and governance), and summarize performance and interoperability drivers arising from larger post-quantum key material.

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