During the last decade, we have lived a kind of “cryptographic peace.” Algorithms like RSA and ECC (Elliptic Curve Cryptography), which form the backbone of TLS, underpin practically everything: from banking transactions to API communications and industrial secrets. However, this foundation has a theoretical expiration date: the arrival of quantum computers capable of breaking these primitives.
Although the “perfect quantum computer” is not yet operating at commercial scale, the threat is already real due to the “Harvest Now, Decrypt Later” strategy. Adversaries can capture encrypted traffic today to decrypt it in the future. For data that must remain confidential for 10 or 20 years, security needs to be updated now.
The solution is Post-Quantum Cryptography (PQC), implemented through hybrid handshakes in TLS 1.3.
1. The Quantum Threat: Why RSA and ECC are at risk
Today’s cryptography relies on mathematical problems that classical computers would take billions of years to solve. RSA is based on factoring large prime numbers, while ECC is based on the discrete logarithm problem.
The “plot twist” is Shor’s Algorithm. On a sufficiently powerful quantum computer, this algorithm can “shortcut” those operations, reducing the time to break them to minutes.
Technical Analogy: Imagine RSA is a puzzle with just two huge pieces; a quantum computer can snap them together instantly. Post-quantum cryptography is like a 10,000-piece puzzle scattered in a dark room — even with quantum power, the brute mathematical work remains immense.
2. Kyber (ML-KEM): The New Key-Exchange Standard
To mitigate the quantum risk, NIST (National Metrology Institute for the United States) standardized Kyber (now officially referred to as ML-KEM). It uses lattice-based cryptography, specifically the Learning With Errors (LWE) problem.
Unlike RSA’s modular arithmetic, Kyber is based on the geometry of complex multidimensional structures. There is no known “quantum shortcut” to solve these lattice problems.
Why Kyber in TLS 1.3?
Kyber was selected because it strikes an ideal balance between security and performance. Its keys are larger than ECC’s, but small enough to be transmitted without collapsing handshake latency.
3. Hybrid Handshake: Security without Betting Everything
Adopting a new algorithm carries risk: what if there is an implementation flaw in Kyber? To avoid “putting all chips” on PQC, the industry uses the Hybrid Handshake.
How it works
The connection establishes two secrets simultaneously:
- Classical Secret (X25519/ECDHE): Protects against today’s attackers.
- Post-Quantum Secret (Kyber/ML-KEM): Protects against future quantum attacks.
The session key is derived from both. To open the door, an attacker would need to break both locks.
4. The Performance Challenge and the Edge Advantage
PQC introduces a cost: larger keys mean larger packets. This can cause network fragmentation and increase connection time, especially on mobile links where TCP Slow Start may limit sending the handshake within a single RTT.
How the Edge mitigates this impact:
- Edge Termination: Performing the PQC handshake close to the user drastically reduces RTT impact when negotiating larger keys.
- Cryptographic Agility: The Edge allows you to enable hybrid cipher suites (like
X25519Kyber768) centrally, without reconfiguring hundreds of origin servers. - CPU Offload: The heavy lattice math is processed on Azion’s distributed infrastructure, preserving your data center resources.
5. Hands-on: How to Test Your Environment Readiness
You can use OpenSSL and cURL to check whether your clients and servers already support hybrid groups.
Note: PQC support depends on specific library builds (such as the OQS - Open Quantum Safe - project).
5.1 Check Hybrid Group Support
Try listing supported groups. Look for names that include “kyber”:
# Note: Requires OpenSSL with OQS provider or experimental buildopenssl list -groups | grep -i kyber5.2 Test a Hybrid PQC Handshake
If your endpoint supports it, you can force the negotiation:
openssl s_client -connect your-domain.com:443 -groups x25519_kyber768 -servername your-domain.com5.3 Measure Latency Impact
Use cURL to measure handshake time (appconnect) comparing a classical connection with a hybrid one:
curl -s -o /dev/null -w "Handshake TLS: %{time_appconnect}s\nTotal: %{time_total}s\n" https://your-domain.com6. PQC Preparation Checklist
Cryptographic agility should be a priority in Zero Trust architecture.
- Data Inventory: Classify data that needs confidentiality for more than 7 years (candidates for PQC).
- Stack Updates: Ensure your CDNs and Edge Services have a clear roadmap for ML-KEM support.
- Hybrid Rollout: Do not disable ECC or RSA; implement Kyber as an additional layer.
- Performance Monitoring: Track p99 handshake metrics after enabling hybrid suites to tune network timeouts.
Conclusion
Post-quantum cryptography is no longer a theoretical exercise; it is a pragmatic response to the risk of future decryption. By adopting hybrid handshakes at the Edge, your company ensures that today’s secrets remain protected tomorrow, regardless of quantum hardware evolution.
The Quantum Era demands resilience. Being at the Edge with the right tools is the first step to ensuring your “cryptographic peace” lasts many more decades.