ContactKey
Who's really calling you?
Free
Grandparent scams, fake bank agents, eerily real AI voices? ContactKey lets you confirm — in a call, chat or video — that the right person is really on the other end.
The digital safeword for family & friends.
Scammers impersonate family, your bank, your boss or the authorities – and with AI, faked voices now sound disturbingly real. ContactKey gives you a simple tool against it: a shared safeword.
How it works:
1. Set it up once, in person: you scan each other's QR code. It takes seconds.
2. From then on, ContactKey always shows you the same safeword, which changes regularly. Say it to each other on your next call or chat – if it matches on both phones, you recognize and identify each other.
No one else can know your safeword.
Privacy by design:
• Fully offline – no servers, no cloud, no telemetry
• No account, no phone number and no email required
• Your keys never leave your phone
• Source-available – the code is auditable
ContactKey helps against:
• Grandparent & emergency scam calls
• Fake bank and support agents
• CEO / fake-boss fraud
• Deepfake voices and videos
• Phishing and social engineering
Perfect for families, friends and teams who want to keep each other safe.
Personal · Simple · Offline
Important: a matching safeword confirms the connection you set up in person – it is not proof and does not replace caution. Whether you share sensitive information on that basis remains your own free decision.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, ISTARIUM, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- ISTARIUM Consulting Group GmbH
- Size
- 41.4 MB
- Category
- Utilities
- Compatibility
Requires iOS 13.0 or later.
- iPhone
Requires iOS 13.0 or later. - iPad
Requires iPadOS 13.0 or later. - iPod touch
Requires iOS 13.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 ISTARIUM Consulting Group GmbH