Julio Gomez
Principal Engineer, AI & Quantum
Office of the CTO
Articles
ML-DSA Certificates on Cisco Routers – IPsec Series, Part 10
4 min read
An ML-DSA-65 certificate is 6x larger than RSA-2048. Part 10 builds the PKI externally, imports it into Cisco routers via PKCS#12, swaps PSK for ML-DSA signatures, and measures exactly what post-quantum authentication costs on the wire.
Post-Quantum Key Exchange on Cisco Routers – IPsec Series, Part 9
7 min read
Three Cisco 8000 routers on IOS XE 26.2. We walk the key exchange from classical to PPK to native ML-KEM-768 hybrid, then prove a phased rollout across hub and spokes works with zero outage.
Mutual Post-Quantum Auth over IKEv2 – IPsec Series, Part 8
5 min read
We mutually authenticate an IKEv2 tunnel: classical ECDSA first, then ML-DSA over an ML-KEM key exchange, and watch the ML-DSA certs balloon the authentication message into six fragments on the wire.
The Great Certificate Size Explosion – IPsec Series, Part 7
6 min read
Hands-on with OpenSSL 3.5: we generate classical and post-quantum certificates and weigh them side by side. Then we sign, verify, and tamper.
Who Goes There? Post-Quantum Authentication – IPsec Series, Part 6
4 min read
Auth is the other pillar, with a sneakier quantum deadline: a live signature need only resist forgery until it's verified, but long-lived trust anchors and slow PKI migration mean roots must go quantum-safe early. We meet ML-DSA and SLH-DSA
A Different Road to Quantum Safety: The PPK – IPsec Series, Part 5
5 min read
A second road to quantum safety: a Postquantum Preshared Key mixes an out-of-band secret into the IKE key schedule that never travels the wire, so even a classical handshake resists "harvest now, decrypt later," on gear not supporting ML-KEM.
Watch a Hybrid Post-Quantum Handshake on the Wire – IPsec Series, Part 4
5 min read
We build a real hybrid IKEv2 tunnel in two Docker containers, capture the packets, and run classical versus hybrid side by side, seeing the extra round trip, ML-KEM fragmentation, and that going quantum-safe costs almost nothing.
ML-KEM vs Diffie-Hellman: The Showdown – IPsec Series, Part 3
3 min read
We put Diffie-Hellman and ML-KEM side by side on size, latency, compute, and security, and land on the smartest move: a hybrid key exchange that runs both and combines their secrets, so an attacker would have to break both at once.
Harvest Now, Decrypt Later: The Threat to Key Exchange – IPsec Series, Part 2
4 min read
We zoom in on key exchange and its urgent "harvest now, decrypt later" threat, where attackers record encrypted traffic today to decrypt once quantum hardware matures. Then we meet the two contenders: classical Diffie-Hellman and post-quantum ML-KEM.