In an upbeat blog post on Saturday, Sebelius released statistics to illustrate the volume of interest in the Affordable Care Act, or Obamacare, and the speed of the “data hub,” one piece of the complex system behind HealthCare.gov.

Sebelius praised the performance of the data hub, which connects to the Social Security Administration and Internal Revenue Service to verify applicants’ identity and income.

She said it took the hub less than 1.2 seconds to route information, and called it “a model of efficiency and security.”

“The Hub is on the job, and so are we,” said Sebelius, who will be grilled about the website by Republican lawmakers at a hearing on Wednesday.