Microsoft is now putting quantum encryption in Windows builds

The biggest fear surrounding quantum computers, which are coming on in leaps and bounds, is that they will be able to smash through classical encryption, allowing anyone with a quantum computer to read any data protected by classical encryption methods. Microsoft, however, is not waiting for quantum computers to become widespread before it better protects users.

At BUILD 2025 today, the company announced that it is integrating post-quantum cryptography (PQC) into Windows Insiders Build 27852 and above, as well as in SymCrypt-OpenSSL 1.9.0 and higher. It said that this will give customers the first opportunities to begin experimenting with PQC within their own environments.

Specifically, Microsoft has made module-lattice based key encapsulation mechanism (ML-KEM) and digital signature algorithm (ML-DSA) available to Windows Insiders through updates to the Cryptography API “Next-Generation (CNG) libraries and Certificate and Cryptographic messaging functions”.

Linux users can also use the SymCrypt algorithm implementations through the OpenSSL API surface provided by the SymCrypt-OpenSSL (SCOSSL) library. The ML-KEM and ML-DSA are some of the first quantum-safe crypto algorithms approved by the National Institute of Standards and Technology (NIST). In December, Microsoft added them to its SymCrypt cryptographic library.

Microsoft hopes that by introducing these algorithms now, rather than waiting until later, it can mitigate the amount of “harvest now, decrypt later” threats where attackers take classically encrypted data and then in the years to come use quantum computers to break the encryption.