Quantum-safe overview

Ensuring a quantum-safe future, together

From climate change to food security, quantum computing can help address some of the world’s biggest challenges. However, we must remain vigilant about potential misuse of scaled quantum computers which could threaten cryptographic algorithms and secure communications. Microsoft is working with governments, global security organizations, and our partners to develop and deploy quantum-safe technologies.

The risk:
Impossible math becomes possible

Most of the data that moves across the internet today – from internet commerce to WiFi access – is secured with public key cryptography, which would take thousands of years for the most powerful computers to break. A scaled quantum computer using Shor’s algorithm, however, could theoretically solve the underlying hard math problem in just a few hours, putting your information at risk.

Today’s cryptography

In public key cryptography, used for most data transfer today, two keys are used: one for encryption, and the other for decryption. These asymmetrical keys, where the public key is shared and the private key is kept secret by the owner, allow secure communication between two parties without sharing the same key. This creates a "trapdoor" for data where anyone can encrypt but only the owner can decrypt.

Shor's Algorithm:
The quantum key to the trapdoor

Shor's algorithm, when implemented on a quantum computer, can efficiently solve the mathematical problems that are the basis of public key encryption. It could theoretically reverse-engineer a private key from a public key by factoring large numbers into primes, something that is considered infeasible for classical computers. This effectively breaks the trapdoor, allowing it to be opened from both sides.

Public key must be updated

Most commonly used public key algorithms, like RSA and Elliptic Curve Cryptography, are vulnerable to Shor’s algorithm. They will need to be replaced with post-quantum public key algorithms currently undergoing standardization by NIST and other standardization bodies globally.

Explore the NIST post-quantum cryptography page

Symmetric key is quantum-safe

Symmetric cryptography is already quantum-safe. Symetric keys are used for data storage and transfer, from ATMs to communications between Azure datacenters. Symmetric systems such as AES and SHA do not rely on mathematics vulnerable to quantum computers – it would take a scaled quantum computer over 7 billion centuries for break AES!

Inventory
and assess

If encrypted data is stolen by hackers today, will it still be relevant in 10 years if a scaled quantum computer is available?

It’s important to understand that for most data, relevance reduces over time. Knowing which data and critical systems to secure now is a first step on the path to a quantum-safe future. Migration to quantum-safe cryptography will take time, and the time to start planning is now.

The path to quantum-safe

Microsoft is working towards a quantum-safe future. This involves securing our products, services, customers, partners, and our entire supply chain. We are prioritizing cryptographic agility and hybrid solutions, integrating standardized post-quantum cryptographic algorithms, and enhancing security processes with dedicated services and training.

Microsoft’s Quantum-Safe Program is helping Microsoft’s customers and partners prepare.

Learn about Microsoft’s Quantum-Safe program

Real data. Actionable insights.

Let Copilot and the Azure Quantum Resource Estimator help grow your understanding of the intersection of quantum and cryptography. Explore the number of qubits and runtime that would be needed for a future quantum computer to break common encryption algorithms.

Explore Cryptography with Copilot now

Illustration of a chart and the Copilot feature in Azure Quantum resource estimator

Dive deeper

The Azure Quantum Resource Estimator provides highly customizable parameters to help cryptographers and security professionals investigate specific algorithms and quantum architectures to generate actionable insights.

Learn about resource estimates for cryptanalysis