Invisv became a carrier that can't tell who you are: blind billing and rotating IMSIs

Privacy researchers Barath Raghavan of the University of Southern California and Paul Schmitt had come up with a technical solution for how phone carriers could stop automatically collecting users' locations — and knew it would be hard to convince telecoms to implement it. So they became the carrier they wanted to see: Invisv, whose Pretty Good Phone Privacy (PGPP) service launched in beta for Android in August 2022, WIRED reported.

The core realization: the only reason carriers track IMSI numbers before letting devices connect to towers is billing — confirming a SIM is paid up. PGPP reduces that check to a yes/no about whether a device should get service, designed so neither Invisv nor the towers know which IMSI is yours. The $90-a-month Mobile Pro plan includes unlimited US data, unlimited EU data at launch and 30 random IMSI changes a month; the $40 Mobile Core plan offers eight changes and 9GB of high-speed data.

Both plans include PGPP's Relay service, which works like Apple's iCloud Private Relay: your IP is visible to the first relay while the destination stays encrypted, and the second relay — provided by CDN Fastly — connects an alternate IP to your request so no single party knows both who you are and what you load. Relay is also sold standalone at $5 a month. At launch there was no iOS support and no voice calling: data only.

Carrier metadata turns routine tower connections into a record of your movements, visible to telecoms and to IMSI catchers (stingrays).

Persuading telecoms was a non-starter, so the researchers built the service themselves to prove the design works.

Billing only needs one bit — paid or not — so the protocol can hide everything else about the customer.

The two-relay split means no single company ever holds both your identity and your browsing.

Ask why the system needs your data at all: if the real requirement is a one-bit answer, build the exchange around the bit, not the identity — and if incumbents won't adopt it, become one.

PGPP shipped in beta for Android in August 2022 with iOS support still in the works and no voice service. 'The reason we're doing this, honestly, is that it's clear nobody else is going to do it,' Schmitt told WIRED. Fastly's Jana Iyengar framed the partnership as investing in privacy as 'fundamental to the future of the internet.'