Concerns regarding the security of many of the most popular public-key encryption systems in use it have been raised by the ongoing development of experimental quantum computing. Importantly, these methods might be broken by sufficiently big quantum computers that are relevant to cryptography. This possibility emphasises how urgently developers must create and deploy quantum-resistant encryption.
What is PQC (Post-Quantum Cryptography)?
Post-quantum cryptography (PQC) uses cryptographic methods to resist quantum computer assaults. In a future with strong quantum machines, RSA and ECC (Elliptic Curve Cryptography) are susceptible because they use mathematical problems that quantum computers, notably Shor’s algorithm, can answer quickly.
PQC seeks to safeguard cybersecurity in the post-quantum age by replacing weak algorithms with quantum-resistant ones. Kyber (for encryption) and Dilithium (for digital signatures) are good contenders for PQC algorithm standardisation by the U.S. National Institute of Standards and Technology (NIST).
Thankfully, post-quantum cryptography (PQC) provides a method of reducing these hazards using currently available hardware and software. Technology suppliers worldwide are now allowed to begin PQC migrations because to the National Institute of Standards and Technology’s revised PQC standards, which were released in August 2024 after years of community involvement.
Google Cloud is presenting the preview of Google Cloud Key Management Service‘s (Cloud KMS) quantum-safe digital signatures (FIPS 204/FIPS 205) for software-based keys. Additionally, It is providing a high-level overview of their post-quantum plan for Google Cloud encryption products, such as their Hardware Security Modules (Cloud HSM) and Cloud KMS.
Risks associated with post-quantum computing are taken seriously at Google. In addition to implementing additional quantum-computing safeguards in Google Chrome, Google’s data centre servers, and in experiments for connections between Chrome Desktop and Google products (like Gmail and Cloud Console), It started testing PQC in Chrome in 2016 and have been using it to secure internal communications since 2022.
Quantum-safe Cloud KMS
Google Cloud’s efforts to make Google Cloud KMS quantum-safe are ongoing. It’s all-encompassing strategy for quantum safety consists of:
- Providing support for standardised quantum-safe algorithms in hardware and software.
- Facilitating the adoption of PQC by providing migration routes for current keys, protocols, and customer workloads.
- Ensuring that Google’s fundamental infrastructure is quantum-proof.
- Evaluating the performance and security of PQC implementations and algorithms.
- And provide technical feedback on PQC lobbying initiatives in governmental and standards bodies.
The NIST post-quantum cryptography standards (FIPS 203, FIPS 204, FIPS 205, and future standards) will be supported in both software (Cloud KMS) and hardware (Cloud HSM) according to It’s Cloud KMS PQC roadmap. Customers may use this to create digital signatures, execute encryption and decryption operations, and import and exchange keys in a quantum-safe manner.
Google Cloud will make their underlying software implementations of these standards accessible as open-source software for Cloud KMS customers. In order to give its clients and the larger security community complete transparency and code-auditability of their algorithmic implementations, they will also be maintained as a component of the open-source cryptography libraries BoringCrypto and Tink, which were created by Google.
In order to successfully implement quantum-safe cryptography for Google Cloud’s clients, It is collaborating closely with Google Cloud External Key Manager (EKM) partners and HSM manufacturers from a hardware and third-party vendor standpoint.
Now preview quantum-safe digital signatures in Cloud KMS
Customers may now utilise their current API to cryptographically sign data and check signatures using NIST-standardized quantum-safe cryptography with key pairs stored in Cloud KMS with Cloud KMS’s new offering of quantum-safe digital signatures. This makes it possible to evaluate and incorporate these signature schemes into current processes before they are widely used.
Additionally, it can assist guarantee that recently created digital signatures are impervious to attacks by potential adversaries who could possess quantum computers with cryptographic implications. In the same way that the Harvest Now, Decrypt Later (HNDL) threat model emphasises how urgent it is to future-proof key exchange protocols, implementing quantum-safe Digital Signature Algorithms (DSA) now is crucial for preventing future forgeries and tampering and for facilitating safe software updates in a world where quantum computers are relevant to cryptography.
Deploying long-lived roots-of-trust or signing software for devices controlling critical infrastructure should think about mitigating strategies against this threat vector, even if that future could be years away. The basis of confidence in the digital world will grow more robust the sooner it can protect these signatures.
Google Cloud provide support for both SLH-DSA-SHA2-128S (FIPS 205, a stateless hash-based digital signature) and ML-DSA-65 (as defined in FIPS 204, a lattice-based digital signature), which were recently included in NIST’s PQC standards.
The hybridisation of classical and post-quantum digital signatures is one of the many aspects of PQC that is continually evolving and changing. It has chosen not to provide API support for hybridisation techniques at this time since the cryptographic community has not yet reached an agreement and established standards surrounding digital signature hybridisation. This may alter, though, if industry-wide agreement on hybridisation standards solidifies over the next few months.
Moving forward
Google Cloud pledge to keep up with post-quantum cryptography advancements, including implementing any upcoming NIST algorithm standards. As the field of quantum cryptanalysis develops over time, It is ready to adjust to any changes that may occur, especially if cryptanalysis in the future reveals threats that would significantly compromise the security of Google Cloud users or their data.
