Is the Public Cloud Ready for Post-Quantum Cryptography?

In 2023, I published a blog post titled " is and what problem it comes to solve.


Post-Quantum Cryptography (PQC) is a new kind of encryption designed to protect data from powerful quantum computers. Quantum computers can break current encryption methods like RSA and ECC, which rely on hard math problems. PQC uses new math problems that even quantum computers can't easily solve, keeping data safe in the future.


If standard encryption algorithms and protocols are broken by quantum computing, the security of encrypted data and communications would collapse.


The consequences would include:

• Encrypted data today could be recorded and decrypted later by anyone with a powerful enough quantum computer ("harvest now, decrypt later").
  


• Confidential communications, financial transactions, and private information would be exposed.
  


• Digital signatures protecting software updates and identities could be forged.
  


• Public key infrastructures (PKI) and internet security relying on current cryptography would be compromised.
  


• Widespread privacy breaches, economic damage, and loss of trust in digital systems could ensue.
  


• Cybercrimials, nation-states, and hackers would gain unprecedented access to sensitive information.
  

The new algorithms

Currently, several cryptographic algorithms are vulnerable to quantum computing due to their reliance on mathematical problems that quantum computers can solve efficiently:

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  – Used in many secure communications, cryptocurrencies, and authentication systems.
  


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  - a post-quantum cryptographic algorithm standardized by NIST as FIPS 203. It is a key encapsulation mechanism (KEM) used to establish a shared secret key securely between two parties communicating over a public, insecure channel.
  

ML-KEM replaces existing classical key establishment algorithms vulnerable to quantum attacks, specifically:


RSA (Rivest-Shamir-Adleman) - Like RSA, ML-KEM allows encrypting a symmetric key, which is then used for encrypting data.


ECDH (Elliptic Curve Diffie-Hellman) - Like Diffie-Hellman (DH) or Elliptic Curve Diffie-Hellman (ECDH), ML-KEM provides a way for two parties to securely agree on a shared secret key over an insecure channel.

AWS ACM (Certificate Manager)

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  Hybrid Post-Quantum TLS Key Exchange: ACM supports hybrid key agreement protocols combining classical ECDH with the ML-KEM algorithm. This hybrid approach protects TLS connections from quantum computer attacks, ensuring forward secrecy and mitigating "harvest now, decrypt later" risks.
  


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  Quantum-Resistant Cryptographic Algorithms: ACM integrates the latest NIST-approved post-quantum cryptographic algorithms, including ML-KEM for key encapsulation based on CRYSTALS-Kyber.
  

Reference:

Amazon CloudFront

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  Hybrid Post-Quantum TLS: CloudFront supports hybrid post-quantum key exchange mechanisms, which combine classical ECDH with ML-KEM. This hybrid approach ensures quantum resistance while maintaining compatibility with existing TLS protocols.
  


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  TLS 1.3 Support: CloudFront has introduced a TLS 1.3-only security policy that enforces use of the latest, most secure TLS version and supports post-quantum cryptography algorithms in the handshake.
  


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  Supported Curves and Algorithms: The platform supports traditional elliptic curves (prime256v1, secp384r1, X25519) along with PQC algorithms like ML-KEM for the key exchange component.
  

Reference:

Additional references from the official AWS documentation:

Google Cloud

Google Cloud began publishing articles, conducting research, and contributing to post-quantum cryptography (PQC) standards as early as 2016.


I have researched Google's official service documentation, and here are the services that currently support PQC:

Cloud KMS (Key Management Service)

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  Post-Quantum Key Encapsulation Mechanisms (KEMs): Cloud KMS has introduced support for post-quantum KEM algorithms standardized by NIST, including ML-KEM, which is designed to resist attacks from quantum computers. This enables quantum-safe encryption key generation, encapsulation, and decapsulation.
  


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  Quantum-Safe Digital Signatures: Cloud KMS supports NIST-approved PQC digital signature standards like ML-DSA and SLH-DSA. This allows customers to create and verify digital signatures that remain secure against quantum adversaries.
  


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  Hybrid Cryptographic Protocols: Cloud KMS recommends adopting high-level standards like Hybrid Public Key Encryption (HPKE) to integrate post-quantum KEMs alongside classical cryptography for a smooth transition and compatibility.
  


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  Cloud Network Encryption: Internal Google and Google Cloud-native services have migrated traffic encryption key exchanges to ML-KEM, ensuring quantum-resistant network encryption by default.
  

Reference:

Summary

The blog explores whether public cloud providers—AWS, Azure, and Google Cloud—are ready for post-quantum cryptography (PQC), a new generation of encryption algorithms designed to protect against quantum computer attacks. PQC aims to replace traditional algorithms like RSA, ECC, and Diffie-Hellman, which quantum computers could eventually break.


AWS appears to lead adoption, with multiple services (KMS, ACM, Secrets Manager, CloudFront, and Transfer Family) already supporting hybrid post-quantum TLS and digital signatures. Azure and Google Cloud also integrate PQC into key management and identity services, but their implementations are less visible in official documentation and primarily discussed through technical blogs.


I am not an expert in post-quantum cryptography, and this topic remains an evolving area of research and standardization. While NIST has finalized initial PQC standards, cloud provider adoption is still a work in progress.


Disclaimer: AI tools were used to research and edit this article. Graphics are created using AI.

About the author

Eyal Estrin is a seasoned cloud and information security architect, and .


The opinions expressed here are his own and do not reflect those of his employer.