Key points
- Only TLS 1.3 offers protection against quantum computing threats when configured correctly.
- All versions of SSL and TLS 1.0/1.1 must be disabled immediately.
- Hybrid post-quantum algorithms are now standardized for TLS 1.3 key exchange.
The UK National Cyber Security Centre has issued strict new guidance requiring system administrators to adopt TLS 1.3 and disable all older, insecure protocols to prepare for future quantum computing threats.
How it unfolded
- The UK NCSC published updated recommendations for configuring TLS securely and transitioning to post-quantum cryptography.
- The agency specified that only TLS 1.3 provides necessary protection against quantum attacks when properly configured.
- Guidance mandates the immediate disabling of all SSL versions and TLS 1.0 and 1.1.
Who is affected
System administrators responsible for configuring servers or clients within their organizations are the primary audience for this guidance. Government systems are explicitly advised not to support deprecated protocol versions. The recommendations apply to personal, enterprise, and OFFICIAL-tier government information protection. Teams managing private public key infrastructures may adopt post-quantum authentication sooner than those relying on the public web PKI, where standardization is still ongoing.
What happens next
Organizations using TLS 1.2 should develop a plan to migrate to TLS 1.3 to adopt post-quantum cryptography. The NCSC notes that TLS 1.2 will not receive new features, only critical security updates. Work is ongoing to standardize post-quantum authentication in TLS and the wider web PKI. Once these standards are finalized and mature implementations are available, the guidance will be updated to include recommendations for their use.
The background in plain language
Transport Layer Security encrypts data moving between servers and clients. Older versions like SSL have known weaknesses that attackers can exploit. New quantum computers could break current encryption methods. Post-quantum cryptography uses math that quantum computers cannot easily solve. Hybrid schemes combine old and new methods for safety. Teams usually test new protocols in isolated environments before wide deployment. Check whether legacy applications depend on old protocols. Verify that server configurations match current security standards. Ensure certificates are managed correctly to avoid service outages during transitions.
What to do and how to stay safe: TLS
- Audit current server and client configurations to identify any use of SSL, TLS 1.0, or TLS 1.1.
- Plan a migration path from TLS 1.2 to TLS 1.3 to prepare for post-quantum cryptography adoption.
- Monitor vendor updates for mature implementations of hybrid post-quantum key exchange mechanisms.
Step-by-step guide: Mobile Device Security for Small Business: Control Without Cost
General security guidance from the Circuit Observer newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
Why is TLS 1.2 no longer recommended for long-term security?
TLS 1.2 will not receive new features, only critical security updates, and does not support post-quantum cryptography.
What is post-quantum cryptography?
It is a type of cryptography designed to be secure against attacks from both classical and quantum computers.
Are non-hybrid post-quantum algorithms ready for use?
The NCSC considers non-hybrid ML-KEM algorithms acceptable for use in TLS, and they are available in many implementations.
