Erseni Vault is the GDPR-compliant, EU-hosted zero-knowledge tool for tax advisers: you send a request link, the client enters their accounting, banking and tax-portal logins along with financial records, you collect them once. Then the link is dead, and nothing is ever stored in plaintext on the server.
Every project starts the same way: you need access, and the client sends it the fastest way they know.
Every engagement starts with a pile of credentials: the accounting login, the online-banking PIN, the tax-portal certificate, plus payslips, bank statements and balance sheets. Clients send it all by email, WhatsApp or as a photo of a scribbled note, because they do not know any better. This highly sensitive financial data then lingers in inboxes and chats indefinitely, readable by anyone who gains access to a single device. Under the GDPR and your professional duty of confidentiality this is no trivial matter, it is a liability for the practice.
Three steps, no account needed on the client side.
Define which credentials you need (accounting, banking and tax portals) and send the client a single link. Your browser generates the key pair; the private key never leaves your device.
The client opens the link and fills in the fields. Everything is encrypted in their browser against your public key before it is sent. The server only ever sees ciphertext.
You retrieve the credentials a single time and decrypt them locally. Afterwards the payload is deleted on the server and the link is dead. Nothing is left in an inbox.
Zero knowledge is not a promise here, it is the architecture, and the source code is public.
Encryption and decryption happen in the browser (AES-GCM-256, X25519). We store ciphertext and metadata, never the key, never the plaintext.
Data minimisation, one-time reads, short retention. Credentials that no longer exist on any server cannot leak in a breach, which makes your processor duties a lot easier.
Servers and backups stay inside the European Union. No transfer to third countries, no US cloud provider in the request path.
Set up your agency account in under a minute and send the first request link right away. Your clients do not need an account.
Free tier, no credit card, no sales call.