How Budgero Zero Knowledge Architecture Works

When I say Budgero is private by design, I mean it.
For users who want to know how it actually works under the hood, here’s the breakdown.

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Key Principles

1. End-to-End Encryption (E2EE)

   • Data is encrypted on the client before it ever leaves your device.
   • Servers only store ciphertext, never plaintext.

2. Zero-Knowledge

   • The encryption keys are derived from your master password.
   • Budgero servers never see, transmit, or store your keys.
   • Without your password, your data cannot be decrypted — not even by me as the developer.

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Encryption Algorithms

Budgero uses industry-proven cryptography:

• AES-256-GCM for encrypting all budget data.

  • AES-256 = Advanced Encryption Standard with 256-bit keys.
  • GCM mode = ensures both confidentiality and integrity (it’s authenticated encryption).

• Argon2id for key derivation.

  • This protects against brute-force and GPU attacks.
  • Every time you enter your password, Argon2id derives the actual encryption key.
  • Includes configurable time cost, memory cost, and parallelism so it’s resistant to large-scale cracking attempts.

For legacy environments, Budgero can also fall back to PBKDF2-HMAC-SHA256, but Argon2 is the default and recommended.

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How Key Derivation Works

1. You choose a master password during setup.
2. Budgero combines this password with a unique random salt generated on your device.
3. Argon2id runs the password + salt through thousands of iterations, producing a strong 256-bit key.
4. That key is then used by AES-256-GCM to encrypt your budget database.

The salt is stored alongside the ciphertext, but the password is never stored. This way, even if someone stole the database, they couldn’t brute-force it cheaply.

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Local Storage & Sync

• Locally, Budgero keeps an encrypted SQLite database.
• When syncing to the cloud, only the ciphertext is transmitted.

👉 That means your data is never decrypted in transit or on the server. The only place it’s readable is on your device with your password.

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Limitations & Trade-offs

• If you forget your master password, your data is unrecoverable.
• Strong passwords are strongly recommended (use a password manager).
• Argon2 adds a small delay (~100–300ms) during login, but that’s the cost of security.

I believe this trade-off is worth it: a tiny slowdown at login for much stronger privacy.

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Conclusion

Budgero’s encryption design is built around proven algorithms (AES-256-GCM, Argon2) and a zero-knowledge model where your keys never leave your device.

The result:

• Your budget is always encrypted at rest.
• Always encrypted in transit.
• Always under your control.

🔒 Privacy isn’t a feature here — it’s the foundation.

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👉 Curious? Try the demo or join the beta.
Your money, your data — and nobody else’s.