About Solo2
Why Solo2 exists, what problem it solves and who is behind the project.
Why Solo2 exists
The messaging we use every day has become a business that lives on knowing who speaks to whom, when and from where. Even if the content is encrypted, the metadata — who, when, with what frequency — remains the product.
Solo2 was born from a simple idea: a private conversation should not pass through anyone's server. When two people talk over a walkie-talkie, there is no third party in the middle saving the conversation "just in case". Real privacy works the same way: your message leaves your device and arrives at the other person's device, directly.
Solo2 is the translation of that idea into software. No commercial shortcuts, no compromises with privacy, no servers that become an attractive target.
Technical decisions we defend
No message server
Messages travel point-to-point between the two devices whenever possible. Our server only facilitates the initial encounter — like a switchboard that connects a call and steps away.
No phone number
One anonymous identity per user, with no metadata to link to your real life. We don't know who you are, and we never keep track of who you talk to: upon accepting a connection, the record is deleted from the server and the link exists only on your devices.
Outside of app stores
Today, Solo2 is not on the App Store or Google Play: installing from a store would leave a trace in your purchase history. It works as a progressive web app (PWA) directly in your browser, and can be installed without intermediaries. We are preparing a second route via the App Store and Google Play, without changing this one — the confidentiality of your messages will be exactly the same in both. When it becomes available, the choice will be yours.
Real encryption, no backdoors
X3DH for session establishment and Double Ratchet for ongoing encryption — the same primitives as Signal, validated by the academic community. No recovery keys on our servers: if you lose access to your 24 words, we have no way of giving you your account back. It is the only way to do it.
Data in Europe, no transfers
The entire Solo2 infrastructure is hosted in Europe. No transfers to third countries, no subcontractors in jurisdictions outside the GDPR. The little that passes through our server — the moment of the initial encounter — lives and dies in Europe.
Team
Menzuri
Menzuri is the company behind Solo2. Legal name registered as Menzuri Gestión S.L. (NIF B-27228683), based in Spain. We take care of the infrastructure, continuous development and legal compliance.
The Solo2 brand is registered as an EUTM (European Union trademark, number 019357868) with the EUIPO.
Author — R.Eugenio
Has been programming since 1983, the year he taught himself by reading source code on MS-DOS and started working on commercial software. He holds a Bachelor of Science in Computer Engineering from the University of Missouri (Columbia). He is interested in languages, data structures and pure algorithms more than fashions; his career has run mainly between GW-BASIC, C, C++ and Go, and today he is focused above all on Zig.
He has an almost clinical obsession with code economy: a flag must fit in a bit, not a byte or an integer; every processor cycle and every memory read counts. For him, software exists to simplify people's lives, not to complicate them.
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