Dead Drop app for iPhone and iPad
Developer: Ultra Horizon Ltd
First release : 23 Apr 2024
App size: 25.25 Mb
Dead Drop is a secure, private and metadata-free communication platform, designed to work anywhere in the world.
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How it works:
After opening the app, your device will generate a unique set of cryptographic keys that is used to securely communicate with others.
To communicate, you will need to meet up with another user in person and verify each others identity, and then scan each others code to exchange public keys and add one another to your respective contact lists.
For your privacy and security, you can only receive messages or calls from users that are in your contacts list. If you are not in possession of a public key for a particular user, you cannot receive their messages or call requests, eliminating unknown spam and/or malicious messages.
Enjoy communicating securely within your own private group of trusted contact by exchanging keys in person!
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Cryptography and Privacy details:
- The app uses X25519 and Ed25519 keys for your own identity.
- Authenticated HPKE is used to generate a unique symmetric key every time you send a message via X25519 with SHA256 as an encapsulation mechanism and SHA384 for key derivation.
- Messages and calls are end-to-end encrypted using the ChaCha20-Poly1305 AEAD cipher.
- Dead Drop has no knowledge of who you are communicating with, or what is being sent between devices.
- Dead Drops servers act as a Dead Drop location, where your encrypted messages can be left for the other device to pick up within 30 days. Once retrieved, the message or attachment is deleted from our servers, with no logs retained. If a message or attachment is not retrieved from Dead Drops servers before the 30 day expiry, it will be deleted permanently, again with no logs left over.
- You can be added into groups with people that are not on your contact list, but only by trusted people in your contact list.
- Notifications delivered to Apples Push Notification Servers contain no private or identifiable information regarding who your notification is from, or what it is about.