The quantum threat is not a future problem. Adversaries are already harvesting encrypted defense traffic today to decrypt it the moment a cryptographically relevant quantum computer arrives. For the US military and its forward deployed edge, that traffic is command and control, intelligence, and mission data with a shelf life measured in decades.

The mandates have landed. The Department of War Post-Quantum Cryptography Strategy sets hard gates requiring all systems to support quantum-resistant algorithms by 2030 and to run on them by 2031. CNSA 2.0 requires every new National Security System acquisition to be compliant by January 2027. The direction is set. The harder question is execution, because most cryptography in operational use was never inventoried, and the tactical edge, built on constrained devices and legacy links across denied and degraded environments, is where migration breaks down first.

Closing that gap demands more than swapping algorithms. It requires crypto-agility engineered into infrastructure, a realistic sequence for migration under contested conditions, and honest reckoning with the systems that cannot wait until 2031.

Join GIST360’s latest breakfast briefing installment which will convene senior Defense and Military leaders for a candid working session before Day 2 of AUSA on the strategies, tradeoffs, and hard decisions ahead.