WhatsApp Usernames Are Already Raising Impersonation Red Flags

An anonymous reader quotes a report from TechCrunch: WhatsApp this week started rolling out username reservations ahead of the broader launch planned later this year. The feature -- which lets people find and message each other by handle instead of phone number -- is already raising impersonation concerns, drawing scrutiny from security experts and regulators in India, the app's largest market, with more than 500 million users. The rollout marks a shift in how people identify one another on WhatsApp. Instead of relying on phone numbers as the primary identifier, users will increasingly interact through platform-managed usernames, a change that Meta says improves privacy but that critics argue could create new opportunities for impersonation.

[...] Asked about how it protects against impersonation, Meta told TechCrunch it reserves usernames for public figures, government entities, and "some variations" of those names so only the legitimate owner can claim them. The company did not explain, however, how it decides which lookalike usernames get proactively reserved and which don't. The concerns have already reached regulators in India, where cyber fraud schemes frequently exploit messaging platforms to impersonate police, banks, and government officials. [...] Rachel Tobac, chief executive of SocialProof Security, called usernames a net privacy gain because they reduce the need to share phone numbers, which can expose users to SIM-swap attacks, phishing, and account takeovers. Still, she said, lookalike usernames still create opportunities for impersonation. "Ultimately, usernames are a great idea to avoid leaking your phone number to folks you don't know, but it's important to verify identity with the username function too," Tobac told TechCrunch. Her advice for most users: Pick a username that isn't easily guessable, so it's harder for attackers to find you, message you cold, or harass and spam you.

[...] The Mozilla Foundation said the introduction of usernames is likely to bring new tradeoffs. "Increased scams and impersonation from fake handles are potentially a big one," it told TechCrunch. "Checking a phone number can be a useful verification tool, but these harms are also permitted by the platform's fundamental design choices." Mozilla also flagged a broader interoperability question -- one worth logging if you're building on top of, or competing with, Meta's ecosystem. While letting users claim their existing Facebook and Instagram usernames may cut down on impersonation, it also shows how easily Meta can stitch identity together across its own apps, even as users still can't take that identity, or their contacts, to a rival platform. For now, WhatsApp says it is taking a gradual approach to the rollout. "We're taking our time and listening to feedback so that when it rolls out later this year we get it right," the company said in its FAQ.

Read more of this story at Slashdot.