Privacy & Security2 min read
Calls without a phone number: how ID Caller keeps conversations private
On this page
No number, no email, no account: a 12-digit ID, keys generated on your device, contacts only by mutual consent and encrypted peer-to-peer calls. Here is how ID Caller works.
A phone number is one of the most revealing identifiers you own. It is tied to your SIM card and often to your passport, it travels into other people's address books, and anyone who has it can call you — including spammers. When we designed ID Caller, the goal was simple: private audio and video calls that need none of that.
No number, no email, no account
When you open ID Caller for the first time, the app generates a key pair on your device and gives you a 12-digit ID. That is your entire account. There is no sign-up form, no phone number and no email address, so there is nothing personal for us to store or lose.
Calls only between people who agreed
Knowing someone's ID is not enough to call them. Two people become contacts only by mutual consent:
- scanning a QR code in person;
- sharing a one-time code that is valid for 30 minutes;
- sending a request by ID that the other person confirms.
Because only linked contacts can reach you, unsolicited calls are ruled out by the design itself rather than filtered after the fact.
How a call travels
One-on-one calls use WebRTC, the same open technology that powers calls in modern browsers:
- Both devices exchange connection offers through our signaling server, which only passes short technical messages between linked contacts.
- The devices look for the shortest route between them (ICE) and, whenever the network allows it, connect directly, peer to peer.
- Audio and video are encrypted with DTLS-SRTP. The keys are negotiated between the two devices, so the media cannot be read on the way.
- If a direct connection is impossible — for example behind strict corporate or mobile networks — the call goes through a relay. The relay only forwards encrypted packets; it does not hold the keys to decrypt them.
Note
An honest detail about peer-to-peer: in a direct call, the two devices see each other's network address — that is how they reach each other. With ID Caller this only ever happens with people you have explicitly linked with.
What stays on your phone
Your contact list and call history live only on your device. The server keeps the minimum needed to deliver calls, without names, numbers or emails attached. Incoming calls look and ring like regular phone calls, and the app works between iPhone and Android.
Groups
Besides one-on-one audio and video, ID Caller supports group audio calls for up to 8 people — handy for a quick family or team call without creating yet another account somewhere.
Who it is for
- People who do not want to hand out their phone number — to buyers on a marketplace, new acquaintances or temporary contacts.
- Families and small teams who want a simple, private way to talk.
- Anyone tired of spam calls.
ID Caller is available on the App Store and Google Play. Details on data handling are in its privacy policy.