February 1, 2023

Most top websites are not following best practices in their password policies

By Kevin Lee, Sten Sjöberg, and Arvind Narayanan Compromised passwords have consistently been the number one cause of data breaches by far, yet passwords remain the most common means of authentication on the web. To help, the information security research community has established best practices for helping users create stronger passwords. These include: Block weak […]

Phone number recycling creates serious security and privacy risks to millions of people

By Kevin Lee and Arvind Narayanan 35 million phone numbers are disconnected every year in the U.S., according to the Federal Communications Commission. Most of these numbers are not disconnected forever; after a while, carriers reassign them to new subscribers. Through the years, these new subscribers have sometimes reported receiving calls and messages meant for […]

Vulnerability reporting is dysfunctional

By Kevin Lee, Ben Kaiser, Jonathan Mayer, and Arvind Narayanan In January, we released a study showing the ease of SIM swaps at five U.S. prepaid carriers.  These attacks—in which an adversary tricks telecoms into moving the victim’s phone number to a new SIM card under the attacker’s control—divert calls and SMS text messages away […]