Cwtch (/kʊtʃ/ - a Welsh word roughly translating to “a hug that creates a safe place”) is a decentralized, privacy-preserving, multi-party messaging protocol that can be used to build metadata resistant applications.
* **Decentralized and Open**: There is no “Cwtch service” or “Cwtch network”. Participants in Cwtch can host their own safe spaces, or lend their infrastructure to others seeking a safe space. The Cwtch protocol is open, and anyone is free to build bots, services and user interfaces and integrate and interact with Cwtch.
* **Privacy Preserving**: All communication in Cwtch is end-to-end encrypted and takes place over Tor v3 onion services.
* **Metadata Resistant**: Cwtch has been designed such that no information is exchanged or available to anyone without their explicit consent, including on-the-wire messages and protocol metadata.
In recent years, public awareness of the need and benefits of end-to-end
encrypted solutions has increased with applications like [Signal](https://signalapp.org),
[Whatsapp](https://whatsapp.com) and [Wire](https://wire.org) now providing
users with secure communications.
However, these tools require various levels of metadata exposure to function,
and much of this metadata can be used to gain details about how and why a person
is using a tool to communicate. [[rottermanner2015privacy]](https://www.researchgate.net/profile/Peter_Kieseberg/publication/299984940_Privacy_and_data_protection_in_smartphone_messengers/links/5a1a9c29a6fdcc50adeb1335/Privacy-and-data-protection-in-smartphone-messengers.pdf).
Additionally, any solution to decentralized, metadata resistant communication faces [fundamental problems](https://code.briarproject.org/briar/briar/-/wikis/Fundamental-Problems)
when it comes to efficiency, privacy and group security (as defined by [transcript consensus and consistency](https://code.briarproject.org/briar/briar/-/wikis/Fundamental-Problems)).
Modern alternatives to Ricochet include [Briar](https://briarproject.org), [Zbay](https://www.zbay.app/)
and [Ricochet Refresh](https://www.ricochetrefresh.net/) - each tool seeks to optimize for a different
set of trade-offs e.g. Briar seeks to allow people to communicate [even when underlying network infrastructure
is down](https://briarproject.org/how-it-works/) while providing resistant to metadata surveillance.
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The Cwtch project began in 2017 as an extension protocol for Ricochet providing group conversations via
untrusted servers, with an eye to enabling decentralized, metadata resistant applications (like shared lists
and bulletin board)
An alpha version of Cwtch was [was launched in February 2019](https://openprivacy.ca/blog/2019/02/14/cwtch-alpha/), and
since then the Cwtch team (run by the [Open Privacy Research Society](https://openprivacy.ca)) has conducted
research and development into cwtch and the underlying protocols and libraries and problem spaces.