Privacy Engineering
Privacy between two.
No exceptions.
A communication tunnel where only two people exist. Architecture designed to make interception technically impossible.
Create private tunnelZero-Trust Architecture
Not even we can access your communications.
It's not a privacy policy. It's a deliberate technical limitation.
End-to-end encryption
Your master key is generated with 256 bits of real entropy — the same level as Bitcoin. Each message is encrypted with a unique key that is destroyed afterwards. Your password protects access. Your 24 words protect your data.
Direct P2P connection
When possible, data goes directly between devices. The server only handles the initial introduction.
No storage, no metadata
Messages are not stored on any server. We also do not store who you talk to, when, or how often. No content, no metadata, no trace.
Impossible to hand over
If someone requests your data, we have nothing to hand over. It's not that we don't want to. We simply can't.
5 layers of security
Your password connects you to the service. Your 24 words protect your identity. Your device secret protects your vault. And each message uses a key that is destroyed afterwards.
Two factors without complications
Your account is protected by something you know (your password) and something you have (your device). No authenticator apps, no SMS, no USB keys. The second factor is invisible — your device generates it automatically.
Use cases
Designed for relationships that demand confidentiality
Each Solo2 tunnel is exclusive between two people. No groups. No leaks. No exceptions.
Lawyer — Client
Professional privilege requires infrastructure to guarantee it. Privileged communication with the technical certainty that no one else can access it.
Compliant with GDPR confidentiality and professional privilege requirements.
Doctor — Patient
Health data with the level of protection it deserves. Consultations, follow-ups and sensitive communication without intermediaries.
Designed to comply with health data regulations.
Parents — Children
A private digital space between parent and child. Where they can talk without anyone else — not even the platform — seeing the conversation.
The digital refuge your family deserves.
Partners — Confidential
Negotiations, strategies and decisions that must stay between two people. No risk of leaks or unauthorized access.
Protection of trade secrets and intellectual property.
Couples
The intimacy of a relationship shouldn't pass through third-party servers. An exclusive tunnel where only the two of you exist.
Technical transparency
How we protect your communication
Two connection modes, both with end-to-end encryption. You always know which mode you are in: the app tells you in real time.
Communication without witnesses
When both devices can connect directly, data travels from your device to your contact's without passing through any intermediate server.
Your device → Internet → Their device
✓ The server sees nothing
The blind mirror
When a direct connection is not possible (mobile networks, firewalls), data is relayed through our server. But it travels encrypted: the server relays packets it cannot decrypt, like a mirror that transmits without being able to see what it transmits.
Your device → [Mirror] → Their device
✓ E2E encrypted: the mirror cannot read
In both cases, encryption keys only exist on the participants' devices. Neither Solo2 nor anyone can decrypt the communication.
Process
Three steps to total privacy
Create your account
Choose a username. Solo2 generates your master key and your 24 security words. Your key is encrypted with your password before leaving your device.
Invite your contact
Share your connection code with whoever you want to connect with. A link, a QR, or simply the 8 letters of your code.
Connection established
Private tunnel active. We disappear from the equation.
Frequently asked questions
Total transparency
What data does Solo2 store?
→ A username and a public name (both can be made up), a hash of your password, and your encrypted master key — an opaque blob our server stores but cannot read. No email. No phone. Zero stored messages. When you establish a tunnel, the two peers' identifiers are held in RAM only for the milliseconds the connection takes, then erased. They are never written to disk.
Can Solo2 read my messages?
→ No. Technically impossible. Your master key is randomly generated on your device and never leaves it. Each message is encrypted with a unique key that is immediately destroyed. And we really don't even know who you are. If you want to verify this, spend an afternoon talking about telescopes or fishing rods over Solo2. Wait a few days. No ads on those topics will appear anywhere.
What happens if authorities request data?
→ We only have a username, which can be made up. The content of your communications does not exist in our systems.
Do you have access to my card details?
→ No. European PCI-DSS gateway. We never see or store your banking details. Furthermore, our billing records are not linked to any user account — they are anonymous cash tickets. We cannot know who paid for what.
Who is behind Solo2?
→ Menzuri Gestión SL, Lugo, Spain. European GDPR. We're not an opaque multinational. We're here and we're going to stay here.
How secure is my password?
→ Your password protects access to the service. But the real security lies in your 24 words: a master key of 256 bits generated randomly — the same level as Bitcoin, but with an extra layer: you also need your physical device. Your original password never reaches our servers.
What happens if I lose my device?
→ Your identity is protected by two independent keys: your password (to connect to the server) and your 24 words (your real master key). With either one you can recover your identity. But your data — messages, files, contacts — lives only on your devices. If you lose your only device, the data is lost. That's not a bug: it's security taken to the extreme. It's your data, on your devices, not on our servers.
Can I protect myself against data loss?
→ Yes. Use Solo2 on more than one device. When both are connected at the same time, they automatically sync their vaults. If you lose one, the other has the copy. You can also export an encrypted backup of your identity.
What happens if your server disappears?
→ Your data survives. With your 24 words you can access your local vault without a server. Your data is yours, on your devices. Even if we disappear, you still have access to your data.
How much does Solo2 cost?
→ Solo2 costs 10 cents a day — only the days you have it active. You control when you pay: inside the app there's a switch to pause and reactivate your account. While paused, nothing is charged. Your vault with your data remains accessible offline. The minimum top-up is 3€.
What payment data does Solo2 have?
→ Solo2 only knows your current balance — a number in cents. It doesn't store top-up history, payment dates, or any financial statement. Payments are processed by MenzuriPay, a completely separate system. MenzuriPay records the transaction for legal obligations, but that record is deliberately unlinked from your Solo2 account.
Can I pay anonymously?
→ We currently accept cards through our European payment gateway. We're working on anonymous payment methods: prepaid cards (like Paysafecard) and cryptocurrencies. When available, you'll be able to top up without anyone — not even the payment gateway — knowing who you are.
What happens if there's an error in my balance?
→ We can't fix it. Solo2 doesn't store payment history or daily charge records. It only knows your current balance. If there's a discrepancy, we have no way to verify what happened. This is a deliberate consequence of the privacy design: what isn't recorded can't be leaked. That's the price of real privacy.
Solo2 is not a product. It's a reaction.
A response to a world where intrusive governments and tech multinationals have made private communication impossible.
A breath of freedom from those who have turned your data into their business.
"For some it is a vital necessity. For others, an act of digital sovereignty."
"A bee doesn't waste its energy trying to convince a fly that honey is better. Some minds aren't made for change. Save your energy for what truly matters."
Digital sovereignty
Your data is yours. For real.
Your master key has 256 bits of real entropy — exactly the same security that protects Bitcoin wallets.
But Solo2 goes one step further: even if someone steals your 24 words, they also need your physical device
Your data lives on your devices. Your 24 words are in your possession. You don't need our server to access your information.
Even if we disappear, you still have access to your data.
Server in Germany. DNS in Switzerland. Company in Spain. No dependencies on US companies. No Cloudflare, no Amazon, no Google Cloud. Everything subject to European legislation (GDPR), not American laws.
Why isn't Solo2 free?
Because if the product is free, you are the product. Your data, your metadata, your profile. That's how free internet services work. Solo2 exists precisely so we don't have your data. If we don't sell your data and we don't show ads, the only honest way to keep the service running is to charge you directly. 10 cents a day — about 3 euros a month. No tricks, no fine print, no you being the merchandise.
No risks. No surprises.
7-day free trial
All features, no limits, no credit card. A full week to try everything.
Prepaid balance, billed monthly in arrears
You add credit whenever you want. Only actual usage is deducted at the end of each month. If the service were unavailable on any given day, that day is not counted.
Anonymous payments by design
Your payments are not linked to your account — they are anonymous tickets. This protects your identity, but it also means we cannot process refunds: we do not know who paid.
No commitment
Cancel whenever you want, with no penalties.
Transparent in price too
Only the days you have it active. You control when you pay.
10 cents a day
Pause whenever you want. Reactivate when you need it. No commitment, no fine print.
Free trial to start. No card required.
90 days of grace
If you run out of balance, your account pauses automatically. You have 90 days to top up. Your data remains on your devices.
Minimum top-up: 3€
We don't retroactively charge paused days
Your payments, separated from your identity
Payments are processed by MenzuriPay, a system separate from Solo2. Solo2 only knows your current balance — it doesn't store top-up history or charge records.
We're working on anonymous payment methods (prepaid cards, cryptocurrencies) for those who want total anonymity.
"The cloud is not an abstract, safe entity. It's someone else's computer. Not yours."
That's why your data lives on your devices, not on ours.
Made by people. Improved by people.
We work every day to make Solo2 as secure as possible. But we're human. If you find something that doesn't work well or you have an idea to improve it, we want to know. Inside Solo2 you have a direct channel to talk to us. The only thing we'll know about you is what you write there and the name you chose when you signed up. Nothing more.
Real privacy.
Not marketing promises.
A tunnel where mathematically only two people can exist.
Create private tunnel