Apple WebKit proposes privacy-focused compromise for ad-tracking in Safari web browser
Apple’s WebKit team carries out coding for the Safari browser, and has called its solution “Privacy Preserving Ad Click Attribution”.
It should be remembered that Apple remains strongly in favour of privacy for its users. Last year for example CEO Tim Cook publicly called for federal privacy laws and vowed to protect users’ data and privacy.
Cook also used that speech to take another thinly veiled swipe at some of the biggest social networking companies in the world.
That stance came after Apple in June 2018 declared that it would halt the data gathering activities by the likes of Facebook with the release of new versions of its iOS and Mac operating systems.
And now it has put some flesh on the bones of this strategy, when it opened up about its ad-tracking solution in a highly detailed blog posting about its solution that recognises that despite the privacy issues, ad-tracking is still needed by many websites for funding reasons.
Apple believes that its solution is the best compromise for both consumers and advertisers, and it hopes it will become a standard for all browsers, and not just Safari.
“A typical website is made of numerous components coming from a wide variety of sources,” blogged Apple web engineer John Wilander. “Many of the sources that make up a website are opaque to the user, and some third-party resources are designed to identify and track users as they browse the web, often in order to retarget ads and measure ad campaign effectiveness.”
“The combination of third-party web tracking and ad campaign measurement has led many to conflate web privacy with a web free of advertisements,” said Wilander. “We think that’s a misunderstanding. Online ads and measurement of their effectiveness do not require Site A, where you clicked an ad, to learn that you purchased something on Site B. The only data needed for measurement is that someone who clicked an ad on Site A made a purchase on Site B.”
“Today we are presenting a new technology to allow attribution of ad clicks on the web while preserving user privacy,” he added.
Essentially, the catchy named ‘Privacy Preserving Ad Click Attribution For the Web’ allows for a way of providing click attribution (linking an ad click to an event like a purchase) which on the one hand allows advertisers to the effectiveness of an advert, but doesn’t utilise potentially invasive cross-site tracking.
“Users should not be uniquely identified across websites for the purposes of ad click attribution,” wrote Wilander. “This means the combined data of an ad click and a conversion should not be attributable to a single user at web scale.”
He provided the following example as an explanation of the solution.
“An online store runs an ad on a search engine website,” he wrote. “If a user clicks the ad and eventually buys something, both the online store and the search engine website where the ad was placed want to know; they want the purchase to be attributed to the ad click so that the store knows where to focus their advertising budget. Such attribution is used for measurement of which ads are effective.”
Normally this is achieved via Cookies or so-called tracking pixels (an invisible image).
“We propose a modern way of doing ad click attribution that doesn’t allow for cross-site tracking of users but does provide a means of measuring the effectiveness of online ads,” he wrote. “It is built into the browser itself and runs on-device which means that the browser vendor does not get to see what ads are clicked or which purchases are made.”
“Critically, our solution avoids placing trust in any of the parties involved – the ad network, the merchant, or any other intermediaries – and dramatically limits the entropy of data passed between them to prevent communication of a tracking identifier,” Wilander wrote.
The proof in the pudding will be if the concept is adopted by other browsers.
Mozilla last year announced that its Firefox browser will block advertising trackers (ad trackers) by default.
Even Google earlier this month said that it would roll out ad tracker blocking in its Chrome browser.
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