---
title: "Is Groundwire secure?"
topic: "Security & Privacy"
updated: 2026-07-09
canonical: https://acrobits.net/resources/knowledge-base/is-groundwire-secure/
summary: "Yes, Groundwire supports three layers of encryption: TLS for SIP signaling, SRTP for media (voice), and ZRTP for end-to-end call encryption. Together these help protect call setup, registration, and the audio stream."
---

# Is Groundwire secure?

> Yes, Groundwire supports three layers of encryption: TLS for SIP signaling, SRTP for media (voice), and ZRTP for end-to-end call encryption. Together these help protect call setup, registration, and the audio stream.

Yes, Groundwire supports three layers of encryption: **[TLS](/voip-glossary/tls/)** for SIP signaling, **[SRTP](/voip-glossary/srtp/)** for media (voice), and **[ZRTP](/voip-glossary/zrtp/)** for end-to-end call encryption. Together these help protect call setup, registration, and the audio stream.

## How Groundwire encryption layers work

  - **TLS** encrypts SIP signaling (call setup, registration). Requires your VoIP provider to support TLS on port 5061.

  - **SRTP** encrypts the audio stream between your device and your provider's server. Requires [provider support](/resources/knowledge-base/groundwire-compatibility/); many providers that support TLS also support SRTP.

  - **ZRTP** encrypts calls end to end, negotiated directly between endpoints. Your VoIP provider does not hold the keys. Both sides of the call must support ZRTP; both Groundwire users get this automatically.

## How Groundwire stores SIP credentials

Groundwire stores your SIP credentials locally on your device using the platform keychain. They are not uploaded to Acrobits servers. Push notifications are delivered via SIPIS, Acrobits' push infrastructure (in operation since 2009), without exposing call content.

To turn these protections on, see [How do I enable encryption in Groundwire?](/resources/knowledge-base/how-do-i-enable-encryption-in-groundwire/)

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