Facebook is trying to analyse users’ encrypted messages without reading their texts, says new report

‘Homomorphic encryption’ could let Facebook or third parties perform services without having access to users’ raw data

Adam Smith@adamndsmith
Wednesday 04 August 2021 11:35

Facebook is working to analyse the content of encrypted messages without having to decrypt their contents, according to a new report.

The development is based on “homomorphic encryption”, which allows companies – including Microsoft, Amazon, and Google, who are also working on this technology – to glean information without accessing the texts themselves.

This would allow other companies - including third party companies - to perform analysis of data without giving over the raw data.

“The simplest use case ... is one of when you’re walking down the street and you want to find a coffee shop”, says IBM’s Flavio Bergamaschi. “When do you do that [via your phone, or Google] you are revealing your location, the time of the question ... and that you want a coffee”.

Bergamaschi says this gives a lot of information away, but if that could be done using homomorphic encryption, the entity performing the computation does not know where you are and does not have the ability to decrypt it - but can still can perform the match and return the information.

The approach could help Facebook maintain a level of privacy while also gathering data to be used in its huge ad network, The Information reports.

Facebook, which owns both WhatsApp and Instagram, told the publication that it was “too early for us to consider homomorphic encryption for WhatsApp at this time”, but it seems that Facebook Messages and Instagram direct messages – neither of which are currently encrypted – could use this technology.

Will Cathcart, the head of WhatsApp, also said on Twitter that people should be “skeptical of technical claims that apps like ours could see messages in ‘good’ cases only. That’s just not how technology works.”

That is not to say that WhatsApp does not analyse encrypted messages; in order to help authorities investigate criminals, WhatsApp analyses the unencrypted parts of its platform – the metadata about messages – in order to find anomalies.

This includes how long a WhatsApp group has existed, how many members it has, and how those members interact with other WhatsApp users. It also collects users’ phone numbers and IP addresses, how often users message people, who they message, when they are online, as well as names and profile photos.

It is this approach that Facebook might take to its other messaging services, as part of its long-running plan to link the back-ends of all its platforms.

“As I think about the future of the internet, I believe a privacy-focused communications platform will become even more important than today’s open platforms,” CEO Mark Zuckerberg wrote in 2019.

“I expect future versions of Messenger and WhatsApp to become the main ways people communicate on the Facebook network.”

Such an approach would make it harder for the contents of chats to be uncovered, but would also protect Facebook against legislation that could potentially break it up due to the “buy or bury” strategy government lawyers have alleged against it when it comes to acquisitions of other companies, such as Instagram in 2012 and WhatsApp in 2014.

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