Sachwert-Tresor: A Local, Encrypted Vault for Your Bitcoin, Gold and Silver 👽

Most portfolio apps want an account, an email, often even an exchange login. They pull your prices from the network, store your holdings in the cloud, and end up knowing more about your wealth than you would like.

The Sachwert-Tresor ("tangible-asset vault") does the opposite: a single, local vault for your Bitcoin, gold and silver. Fully offline, no account, no KYC, no cloud. Your data never leaves your device in plaintext.

What it does#

• Bitcoin, gold and silver — record buys, sells and withdrawals. Metals by count × denomination (coin or bar, fineness, dealer).
• Net holdings and value — what you actually hold, plus invested cost. You enter current prices yourself, deliberately without any network lookup, and value and profit/loss are computed from that.
• KYC separation — broker buys (KYC) and private or peer-to-peer purchases (noKYC) stay cleanly separated.
• Tax-tool export — exports manual_buys.csv and manual_sales.csv straight into the format of the BTC tax tool.
• Encrypted backup and sync — the .vault file is fully encrypted and can be synced between devices via Syncthing, without any cloud.
• Bilingual — German and English, switchable in the app.

Why offline?#

A holdings tracker is a map of your wealth. That does not belong on someone else's server.

The Sachwert-Tresor makes not a single network request: no price APIs, no trackers, no external scripts. You enter Bitcoin and metal prices manually. That is less convenient than a live ticker, but it is the price for nobody listening in.

Security, and verifiable#

• Encryption with AES-256-GCM, key derived from your passphrase via PBKDF2-SHA256 (600,000 iterations), all through the browser's native WebCrypto. No third-party crypto code.
• Optional 2FA second factor (Aegis / TOTP, RFC 6238) on unlock.
• No reset, no backdoor. Forget the passphrase and the data is gone, but nobody else gets in either.
• Open source. The full client code is public, so you don't have to trust me, you can check that nothing phones home.

How to get it#

Try it in your browser (desktop and mobile), nothing to install: https://api.alien-investor.org/tresor/

As an Android app (deliberately not via the Google Play Store), now on the Zap Store, the permissionless app store on Nostr: https://zapstore.dev/apps/org.alieninvestor.tresor

The release is signed with a verified identity, and a cryptographic proof links the signing certificate to that identity, so you can check the app is genuinely from me.

Direct download of the signed APK from my own server (also works as an Obtainium source, setup: https://alien-investor.org/en/sachwert-tresor.html#obtainium): https://api.alien-investor.org/downloads/sachwert-tresor/

Source code on GitHub, MIT-licensed: https://github.com/Alien-Investor/sachwert-tresor

Signature fingerprint (identical across all versions): SHA-256: 660f210c7a289f388bb4812c23825a77f1fc84e6a7ee58d64281b6bf5cd87988

More background: https://alien-investor.org/en/sachwert-tresor.html

Your wealth is your business. A tool that tracks it should keep it that way.

#Bitcoin #Gold #Silver #Privacy #SelfCustody #OpenSource #Nostr #Zapstore

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Affiliate block:

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Disclaimer: Some links are affiliate links. Using them supports this channel at no extra cost to you.

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Money, power, Bitcoin — and OPSEC. I write about financial sovereignty, privacy, and cybersecurity in a world built on control. More at alien-investor.org 👽