push.tt / Features
In beta

A two-way call between your own people, end to end encrypted

Push-to-talk is one voice at a time and one direction at a time. Some conversations are not that shape — a supervisor walking somebody through a fault, a handover, a decision that needs both people talking. Those are calls, and between your own staff they stay encrypted.

In beta. Built end to end — the signalling, the relay, the org policy gate, the call screens and the engine on the handset — and covered by tests. But no call has been placed by anyone outside our own testing yet, so we are calling it beta rather than finished.
An incoming push.tt call, labelled an encrypted call before it is answered
An incoming push.tt call, labelled an encrypted call before it is answeredActual product screen
01

Different from push-to-talk on purpose

The radio stays exactly as it is. A call is a separate path, so keying the mic and taking a call are not competing for the same thing.

  • Both people talk at once, with no floor to take and nobody waiting for a release
  • Voice, or voice and video, between members of your organisation
  • Push-to-talk keeps working — the channel does not go quiet because somebody is on a call
A push.tt call in progress: a running timer, and mute, video and speaker controls — a two-way conversation rather than one press at a time
Different from push-to-talk on purposeActual product screen
02

Encrypted between the two handsets

Unlike a telephone call, which has to leave our network for the public phone system, a call between two members of your organisation never needs to be readable by us.

  • Keys stay on member devices; the relay forwards frames it cannot decrypt
  • Video rides the same encrypted channel as the audio rather than a separate unprotected one
  • If a channel is meant to be private, we refuse to carry anything that is not locked — checked by us, not just promised by the app
Encrypted Calls 02
01Keys stay on member devices; the…02Video rides the same encrypted channel…03If a channel is meant to…
Concept diagram Not a product screenshot
03

An administrator decides whether it exists

Calling is a policy question in a lot of operations, and video more so. They are separate switches for that reason.

  • Calls on or off for the organisation, with video as its own toggle beside it
  • Enforced on the relay, so turning video off stops the bytes rather than trusting the app not to send them
  • Defaults chosen so an organisation is never opted into something it did not ask for by an update
Encrypted Calls 03
01Calls on or off for the…02Enforced on the relay, so turning…03Defaults chosen so an organisation is…
Concept diagram Not a product screenshot
04

What is honest about the encryption

The content of a call is end-to-end encrypted. The fact that a call happened is not, and cannot be — the relay has to know who to forward frames to.

  • We can see that two members were on a call, when, and for how long. We cannot see or hear it
  • This is not the same as World Phone: a call to an ordinary telephone number leaves for the public network and is not end-to-end encrypted, and that page says so too
  • Version one has no forward secrecy, which is documented rather than glossed — a limitation stated is worth more than a badge
Encrypted Calls 04
01We can see that two members…02This is not the same as…03Version one has no forward secrecy,…
Concept diagram Not a product screenshot
Features · push.tt

Would your crew use this?

Tell us whether the conversations that matter to you are one-to-one, one-to-many, or need video — it changes what we finish next.