At this time, ZRTP is not yet supported on the Voyced platform.
However, we’re actively monitoring the development of the ZRTP standard and plan to implement support as soon as a stable, widely adopted version is finalised.
What is ZRTP?
ZRTP (Zimmermann Real-Time Transport Protocol) is a method of encrypting the audio (media) stream in VoIP calls, similar in purpose to SRTP, but with some important differences.
ZRTP was developed by Phil Zimmermann (creator of PGP) and is designed to:
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Provide end-to-end encryption of voice traffic
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Work independently of signalling protocols like SIP or H.323
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Negotiate encryption keys directly between endpoints, rather than relying on central servers
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Support optional Short Authentication Strings (SAS) for caller verification
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Work without pre-shared keys or certificates
In short: ZRTP lets two VoIP endpoints agree on encryption during the call, with minimal involvement from the VoIP provider.
How is ZRTP different from SRTP or TLS?
| Protocol | What it secures | Key exchange method | Requires provider support? |
|---|---|---|---|
| TLS | SIP signalling | Pre-shared certificates | Yes |
| SRTP | Voice (media) | Often provider-controlled | Yes (supported by Voyced as passthrough) |
| ZRTP | Voice (media) | Peer-to-peer, negotiated during call | No (but both endpoints must support it) |
ZRTP is appealing for users who want fully peer-controlled encryption, especially in high-security environments, but it still depends on compatible devices or apps on both sides of the call.
When will Voyced support ZRTP?
ZRTP is not yet a standard part of most carrier-grade VoIP systems. Once adoption improves and a stable version is widely supported, we plan to add it to the Voyced platform.
In the meantime, if you need media encryption, we fully support SRTP (via passthrough), and we can enable TLS on request to secure your signalling.
Need help setting up secure VoIP with SRTP or TLS?
Just ask, we’re here to help.
Last updated: 01/04/2025
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Given the fast evolution of the telecom sector, Voyced does not offer any guarantee about the accuracy and completeness of the information offered.
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