Many Australians still remember the 2016 census because of the online outage that dominated headlines on census night. It was the first time a majority of Australians were expected to complete the census online. However, the website crashed, in what became widely known as #CensusFail.

It wasn’t just any crash. The Australian Bureau of Statistics (ABS) took the online census offline after a series of distributed denial-of-service attacks. Known as DDoS, these attacks overwhelm a website with internet traffic, making it unavailable to legitimate users.

While no data was ever leaked, the website was unavailable for almost two days, undermining public confidence in the security of one of Australia’s largest collections of personal information.

Ten years later, the latest census will take place on August 11 2026. This year, around 85% of Australians are expected to complete it online.

The successful 2021 census reflected the cyber security improvements the ABS had made since 2016.

So how secure is the 2026 census? What did its latest cyber security audit find, and what can Australians do to protect themselves from scams while completing it online?

Why the census is an attractive target for cyber criminals

The census is Australia’s largest national data collection exercise.

Although the information collected is protected........

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