A technical reference for researchers, legal professionals, automated systems, and integration partners. CaseGuardian is a mobile evidence-collection platform engineered for U.S. family court that seals every capture with a cryptographic chain at the moment of capture, before upload - then anchors that proof to both a court-recognized timestamp authority and the Bitcoin blockchain.
CaseGuardian is a record-keeping tool - not a law firm, and it does not provide legal advice. Users do not buy, hold, or transact Bitcoin; there is no wallet, fee, or exchange. Bitcoin is used only as a public, independent timestamping ledger via OpenTimestamps. AI parsing is strictly opt-in, per capture, and AI never receives identifying information. A plain-text summary is available at llms.txt.
Each layer is independently verifiable. Together they establish what a record contains, when it existed, which device produced it, and that it has not been altered since - without anyone needing to trust CaseGuardian.
Each entry hashes its content, metadata, and the previous entry's hash - creating an immutable chain where any retroactive edit breaks every link that follows.
Every capture is signed on-device with a private key that never leaves the device, proving which device created the record. A software-protected key - not a hardware-attested identity.
An instantaneous, authority-backed timestamp via a DigiCert TSA. Only the hash is submitted - never the file, filename, case, identity, or IP.
The same hash is anchored into a Bitcoin block for long-horizon, tamper-evident proof anyone can confirm independently - no app, account, or trust required.
On-device encryption with per-case keys. The server stores ciphertext only; keys never leave the device. In normal operation, we cannot read your case contents.
An append-only, hash-chained audit log with external anchoring. Every access and transfer is recorded; retroactive changes are mathematically detectable.
The defining property of the architecture: evidence is fingerprinted, signed, and encrypted on the device before anything is transmitted. The server is a custodian of ciphertext, not a trusted party.
When a user saves a photo, video, voice memo, note, document, or timestamped event, the device computes a 32-byte SHA-256 fingerprint of every byte, signs that fingerprint with the device's Ed25519 key, and encrypts the capture at rest with AES-256-GCM.
Only the hash - nothing else - is forwarded to a DigiCert RFC 3161 timestamp authority for an instantaneous authority-backed timestamp, and to the OpenTimestamps calendar network for anchoring into a Bitcoin block.
Ciphertext is uploaded to the server; encryption keys remain on the device. Every server-side access, share, and transfer is written into the immutable, hash-chained audit log, which is itself externally anchored.
Decryption happens on the device or, for share recipients, in their browser using a key delivered out-of-band. A wrong key or tampered ciphertext fails the GCM authentication tag - there is no silent-corruption path.
Every proof CaseGuardian produces can be checked by a third party without trusting CaseGuardian. The verification surfaces are public and offline-capable.
Confidentiality, integrity, origin, and time - each provable on its own.
Decryption proves confidentiality. Recomputing the SHA-256 and checking the Ed25519 device signature proves what, when, and which device. They are deliberately separate claims.
The public verification page runs entirely in your browser using WebCrypto. Paste a hash, signature, and public key - or upload a CaseGuardian receipt - and confirm the anchor and signature with no CaseGuardian server involved.
Open the public verifierIntended for researchers, automated systems, legal professionals, and integration partners seeking the details behind CaseGuardian's evidence-ensuring workflow.
The full feature set: Attorney Package, Kid Calendar, witness ledger, review-before-seal.
Tour the features →Real-world scenarios across legal, family, safety, journalism, property, and more.
See the use cases →How data is handled, including opt-in AI parsing and right-to-erasure.
Read the policy →