HOW WE ESTIMATE
Q-DAY.

One date, with every input visible.

The current QDayWatch central estimate is 2034. It is the rounded weighted average of five recent inputs: the Global Risk Institute expert survey (45%), Gartner's threat forecast (20%), IBM's hardware roadmap (15%), IonQ's hardware roadmap (10%), and Google's security deadline (10%).

How inputs become years

Direct date forecasts enter as published. For the GRI probability curve, QDayWatch interpolates the point where the average expert likelihood crosses 50%. Roadmap dates enter at the year their published scale approaches cryptographically relevant resources. Every conversion is shown in the homepage table.

X + Y > Z tests the estimate.

X is how long vulnerable data must remain secret. Y is the time required to migrate. Z defaults to the QDayWatch estimate—currently eight years—and can be changed to test other scenarios.

The terms X and Y add because data may continue to be created throughout migration. Data protected on the final day before the transition completes can remain sensitive for another X years.

Result states

When X + Y exceeds Z, the modeled exposure window is open. Equality is shown as a zero-margin threshold. Only X + Y below Z produces modeled migration margin.

Observation is not relevance.

Laboratory demonstration

A result performed under disclosed experimental conditions. It can be significant without being scalable, general-purpose, or cryptanalytically useful.

Resource estimate

A model built from assumptions about algorithms, error rates, cycle times, connectivity, decoding, and architecture. We show dates and assumptions because estimates can change sharply without hardware changing at all.

Cryptographically relevant

A capability sufficient to attack a real production key at meaningful scale and reliability. A toy factoring demonstration is not classified as cryptographically relevant.

Independence and directness determine weight.

Independent expert aggregation receives the largest weight because it combines diverse views. Direct cryptographic threat forecasts rank next. Vendor hardware roadmaps receive smaller weights, and security deadlines receive the smallest weight because they encode institutional risk tolerance as well as technical expectations.

The estimate is recalculated when a source materially changes its forecast, a roadmap milestone is missed or achieved, or a new high-quality expert survey is published.

Uncertainty remains visible.

• Primary sources are preferred over commentary.
• Publication date and event date are stored separately.
• Vendor roadmaps are labeled as plans, never achievements.
• Withdrawn and deprecated standards remain in the historical record.
• Material corrections are reflected in the source record and review date.