Case Study: The City & County of Denver achieves rapid enrollment of 18,000+ users and unified MFA with Duo Security

How the City & County successfully deployed Duo, enrolling over 18,000 users in just three months

The City and County of Denver’s Information Security team, which supports a hybrid environment of on‑prem and SaaS applications during an active digital transformation, faced MFA sprawl from multiple legacy and free authenticators. With sensitive citizen data, a new cloud ERP, and rising phishing attempts targeting credentials, the team needed a single, easy‑to‑manage MFA solution that integrated across SaaS, on‑prem systems, RDP/SSH and a diverse user base including field officers.

They chose Duo for its broad integrations and user-friendly options, phasing deployment by application and using self‑enrollment and mobile push (with FIDO/YubiKey alternatives for restricted or offline environments). The rollout protected over 18,000 users in three months with fewer than 100 help‑desk tickets, met CJIS and PCI requirements, enabled offline authentication for law enforcement, and set the city on a path toward a shared zero‑trust approach.

The City & County of Denver

Paul Kresser

Chief Data Officer