Bugs in our Pockets: The Risks of Client-Side Scanning

by   Hal Abelson, et al.

Our increasing reliance on digital technology for personal, economic, and government affairs has made it essential to secure the communications and devices of private citizens, businesses, and governments. This has led to pervasive use of cryptography across society. Despite its evident advantages, law enforcement and national security agencies have argued that the spread of cryptography has hindered access to evidence and intelligence. Some in industry and government now advocate a new technology to access targeted data: client-side scanning (CSS). Instead of weakening encryption or providing law enforcement with backdoor keys to decrypt communications, CSS would enable on-device analysis of data in the clear. If targeted information were detected, its existence and, potentially, its source, would be revealed to the agencies; otherwise, little or no information would leave the client device. Its proponents claim that CSS is a solution to the encryption versus public safety debate: it offers privacy – in the sense of unimpeded end-to-end encryption – and the ability to successfully investigate serious crime. In this report, we argue that CSS neither guarantees efficacious crime prevention nor prevents surveillance. Indeed, the effect is the opposite. CSS by its nature creates serious security and privacy risks for all society while the assistance it can provide for law enforcement is at best problematic. There are multiple ways in which client-side scanning can fail, can be evaded, and can be abused.


Exploring Encrypted Keyboards to Defeat Client-Side Scanning in End-to-End Encryption Systems

End-to-End Encryption (E2EE) aims to make all messages impossible to rea...

Mobile Encryption Gateway (MEG) for Email Encryption

Email cryptography applications often suffer from major problems that pr...

Re-purposing Perceptual Hashing based Client Side Scanning for Physical Surveillance

Content scanning systems employ perceptual hashing algorithms to scan us...

Thoughts on child safety on commodity platforms

The explosion of global social media and online communication platforms ...

YASM (Yet Another Surveillance Mechanism)

Client-Side Scanning (CSS) see in the Child Sexual Abuse Material Detect...

Chat Control or Child Protection?

Ian Levy and Crispin Robinson's position paper "Thoughts on child safety...

Judge, Jury Encryptioner: Exceptional Access with a Fixed Social Cost

We present Judge, Jury and Encryptioner (JJE) an exceptional access sche...

Please sign up or login with your details

Forgot password? Click here to reset