Digital advertising has a serious problem: fraud.

Widespread fraudulent practices are inflating measures of the traffic that digital ads attract, leading some advertisers to pay higher rates than they should.

Can blockchain fix it?

A handful of blockchain startups believe so. They argue that a shared digital ledger to authenticate and safeguard advertising data, a transparent exchange for trading digital ads, and a special ad-focused browser that pays its users in tokens could each help fix that multibillion-dollar problem.

The industry standard for gauging how much an online ad is worth is the so-called CPM, short for cost per 1,000 views. Less honest players in the industry, however, seek to boost these numbers using bots and other methods that make specific digital ads or ad positioning opportunities appear as if they are getting more traffic than they really are, thus inflating their value.