Arbiter Platform · Digital Evidence & Chain of Custody Division

Engine Technical
Design Document

Architecture, pipeline design, cryptographic specification, and performance validation across eight AI engines for evidence ingestion, chain of custody intelligence, AI-powered analysis, automated redaction, secure prosecution sharing, retention automation, cross-jurisdiction collaboration, and evidence analytics — in an era where seeing is no longer believing.

Engines
8 Evidence Integrity Systems
Formats
255+ Evidence File Types Supported
Court Record
0 Successful Custody Challenges
Classification
Confidential — CJIS Compliant
Contents
Eight Engines
01
Evidence Ingestion & Multi-Source Capture
255+ formats, sub-second SHA-256 sealing, 10TB+ daily capacity with automated metadata extraction
02
Chain of Custody Intelligence
Blockchain-anchored WORM audit trails with zero successful court challenges across 47 jurisdictions
03
AI-Powered Evidence Analysis & Search
Computer vision, speech-to-text, semantic search — reducing days of manual review to minutes
04
Automated Redaction & Privacy Compliance
AI-powered face, plate, and PII redaction with Brady disclosure integration and FOIA automation
05
Secure Sharing & Prosecution Workflow
Encrypted, watermarked, expiring evidence packages with Brady/Giglio compliance intelligence
06
Retention & Disposition Automation
Policy-driven lifecycle management — 40% storage cost reduction, 2.8PB eligible evidence disposed
07
Cross-Jurisdiction Collaboration
Federated search, bilateral custody chains, and GDPR data residency enforcement across agencies
08
Evidence Analytics & Case Intelligence
Utilization-to-outcome correlation, operational dashboards, and predictive resource forecasting
Executive Summary
System Architecture Overview
Arbiter Vault implements a cryptographic evidence integrity architecture across eight engines that transforms digital evidence management from a storage problem into a forensic intelligence function. The platform addresses an existential crisis in the justice system: more than 30,000 prosecutions collapsed in England and Wales due to lost or mismanaged evidence, 4–6% of U.S. prisoners are estimated to be wrongfully convicted, 14% of documented wrongful convictions involved untested evidence backlogs, and the National Registry of Exonerations has catalogued over 3,000 wrongful convictions. Meanwhile, Europol's 2024 Observatory projects that as much as 90% of online content could be synthetically generated by 2026 — meaning that every piece of digital evidence entering a courtroom now carries an implicit question: is this real? The proposed Federal Rule of Evidence 707, released for public comment in August 2025, represents the judiciary's first systematic attempt to address AI-generated evidence admissibility.
Vault's architecture responds to this dual crisis — evidence integrity failure and deepfake proliferation — through three interlocking technical systems: (1) cryptographic sealing at the moment of capture using SHA-256, SHA-3, and BLAKE3 hashing with hardware-rooted device identities and C2PA 2.2 provenance embedding, anchored to permissioned blockchain ledgers with periodic public-chain timestamping; (2) AI-powered evidence analysis using computer vision (face, plate, weapon, vehicle detection), speech-to-text transcription with speaker identification, and semantic search across the entire evidence corpus — reducing hundreds of hours of manual review to minutes while maintaining full audit trail integrity; (3) court-ready authentication packages that satisfy Federal Rules of Evidence 901(a) and 902(13)–(14) for self-authentication, with multi-layer deepfake detection analyzing visual artifacts, acoustic patterns, metadata integrity, and C2PA provenance data. Law enforcement pilot programs — Dubai Police on Cardano, the EU LAW-GAME project on Hyperledger Fabric, and Amber Authenticate on Ethereum — validate blockchain's capacity to secure digital evidence from capture through courtroom verification.
0
Successful Court Challenges to Custody Integrity
255+
Evidence File Formats Supported
94%
Manual Review Reduction via AI Analysis
47
Jurisdictions with Admitted Custody Records
Engine 01
Evidence Ingestion & Multi-Source Capture
The integrity of digital evidence is determined in its first millisecond of existence

If evidence is not cryptographically sealed at the moment of capture — on the device that captured it, before it enters any network or storage system — then every subsequent claim about its authenticity rests on trust rather than mathematics. Vault's ingestion engine eliminates trust from the equation. The system accepts 255+ file formats including MP4, MOV, WAV, HEIC, PDF, PCAP, E01, and forensic extraction bundles from Cellebrite and GrayKey, normalizing them into a unified, searchable repository within seconds. Every file receives an automatic SHA-256 integrity hash at the moment of ingestion, timestamped and sealed before any human touches it. Metadata — GPS coordinates, device serial numbers, officer badge numbers, case identifiers — is extracted and indexed automatically. Upon evidence capture, devices such as body-cams or drones sign digital files using hardware-rooted cryptographic identities, then compute hashes and embed credentials in accordance with the C2PA 2.2 standard, storing provenance metadata within permissioned blockchain ledgers.

255+
Supported evidence file formats across video, audio, image, document, and forensic types
<1s
Time from file arrival to SHA-256 hash generation and custody chain initiation
10TB+
Daily ingestion capacity per agency with parallel processing pipelines
C2PA
Coalition for Content Provenance and Authenticity 2.2 provenance embedding
Evidence Ingestion Pipeline
STAGE 01
Device Capture
Body-cam, drone, surveillance, mobile, IoT. Hardware-rooted cryptographic identity signs the file at origin. C2PA 2.2 provenance metadata embedded before network transmission.
C2PAHW-Root
STAGE 02
Hash & Seal
SHA-256 + SHA-3 + BLAKE3 triple-hash computed on arrival. Timestamp sealed. Hash anchored to permissioned blockchain ledger. File enters WORM storage — immutable from this point forward.
SHA-256Blockchain
STAGE 03
Metadata Extraction
GPS, device ID, officer badge, date/time, case number, incident type. Automated extraction eliminates manual entry errors. CAD/RMS integration links evidence to existing case files.
GPSCADRMS
STAGE 04
Deepfake Screening
Multi-layer authenticity analysis: visual artifact detection, acoustic pattern analysis, metadata consistency verification, and C2PA provenance validation. Results logged to blockchain.
DeepfakeC2PA
STAGE 05
Index & Classify
AI classification by evidence type, severity, case association. Full-text indexing of documents. Thumbnail generation for video. Available for search, analysis, and sharing within minutes of capture.
IndexClassify
Cryptographic Sealing Architecture

The triple-hash architecture (SHA-256 + SHA-3 + BLAKE3) provides defense-in-depth against hash collision attacks that could theoretically allow evidence substitution. If a weakness is ever discovered in any single hash algorithm, the remaining two provide independent integrity verification. Each hash is computed independently, timestamped with a trusted time source (GPS-synchronized NTP), and recorded as an immutable entry on the blockchain ledger. The blockchain implementation uses a permissioned Hyperledger Fabric network with five validating nodes operated by independent entities (the deploying agency, the district attorney's office, the public defender's office, the court, and an independent auditor) — requiring consensus from all five nodes before any custody event is finalized. Periodic anchoring to public blockchains (Bitcoin testnet, Cardano) creates externally verifiable timestamps that no single party or consortium can manipulate.

Deepfake Detection at Ingestion

Every piece of video, audio, and image evidence passes through a four-layer deepfake detection engine at the moment of ingestion, before it enters the evidence repository. Layer 1 (visual artifact analysis): CNN-based detection of GAN fingerprints, face-swap boundary artifacts, inconsistent lighting, and unnatural skin textures at pixel level. Layer 2 (acoustic pattern analysis): spectral analysis of audio for synthesis artifacts, unnatural formant patterns, and voice cloning signatures. Layer 3 (metadata integrity verification): EXIF data consistency, GPS plausibility, timestamp continuity, and device signature validation. Layer 4 (C2PA provenance verification): checking the complete provenance chain against the C2PA 2.2 standard to verify that the content has not been modified since capture. All detection results — including algorithm versions, confidence scores, and specific findings — are logged to the blockchain alongside the evidence hash, creating a permanent record of authenticity assessment.

Engine 02
Chain of Custody Intelligence
Zero successful court challenges — because the mathematics do not lie

Chain of custody is the single most attacked element of digital evidence in court. Defense attorneys challenge who accessed the file, when, from where, and whether it was modified between collection and presentation. Vault eliminates every attack vector. Every action — view, download, copy, export, share, annotate, redact — generates an immutable log entry with the user's identity, timestamp, IP address, device fingerprint, and the specific hash state of the file before and after the action. WORM storage prevents retroactive modification of audit records. If a file is copied for analysis, the copy receives its own chain of custody while maintaining a cryptographic link to the original. If evidence is transferred between agencies, the handoff is logged on both sides with bilateral hash verification. Custody records have been admitted across 47 state and federal jurisdictions without a single successful challenge to evidence integrity — because the chain is not a document, it is a mathematical proof.

0
Successful court challenges to Vault chain of custody integrity
WORM
Write-once audit trails immune to retroactive modification or deletion
47
State and federal jurisdictions with admitted custody records
Blockchain Custody Architecture

Each custody transfer is documented through smart contracts that register custodial changes transparently on the permissioned blockchain. The smart contract validates three conditions before finalizing any transfer: (1) the transferring party's identity is authenticated via ECDSA-P256 digital signature; (2) the file's current hash matches the last recorded hash (confirming no modification since the previous custody event); (3) the receiving party's authorization is confirmed against the case-specific access control list. If any condition fails, the transfer is blocked and an integrity alert is generated. The blockchain provides an externally verifiable audit trail that is independent of the deploying agency — meaning that even if the agency's own systems were compromised, the custody chain on the blockchain remains intact and verifiable by any authorized party. This architecture has survived Daubert challenges because the defense cannot argue that the agency fabricated the custody trail; the trail exists on a distributed ledger that the agency does not unilaterally control.

FRE 901(a) & 902(13)–(14) Compliance

Vault generates court-ready authentication packages that satisfy Federal Rules of Evidence 901(a) ("evidence sufficient to support a finding that the item is what the proponent claims it is") and 902(13)–(14) for self-authentication of certified records of regularly conducted activity. The authentication package includes: the complete custody chain with every access event timestamped and signed; the original hash computed at ingestion and every subsequent hash verification confirming zero drift; the blockchain transaction IDs enabling independent verification; the deepfake analysis report from Engine 01's four-layer screening; and a forensic examiner's attestation template compliant with Daubert standards. The proposed Federal Rule 707, released for public comment in August 2025, applies expert witness reliability standards to machine-generated evidence — Vault's comprehensive provenance documentation is designed to satisfy Rule 707's requirements for demonstrating that AI-generated evidence is "more likely than not authentic."

Engine 03–04
AI Evidence Analysis & Search · Automated Redaction
Days of manual review reduced to minutes — with every AI action logged to the custody chain

Engine 03 processes evidence at machine speed: computer vision detects and classifies faces, license plates, weapons, vehicles, and objects of interest across video and image evidence. Speech-to-text transcription converts recordings into searchable, timestamped transcripts with speaker identification. Semantic search allows investigators to query the entire evidence corpus using natural language — "find all footage of a red sedan near 4th and Main between 9 PM and midnight" — and receive results in seconds. Engine 04 provides AI-powered redaction for privacy compliance: faces, license plates, addresses, and personally identifiable information are automatically detected and redacted in video, audio, and documents. Brady disclosure integration ensures that potentially exculpatory material is flagged before redaction — preventing the constitutional violation of redacting evidence the defense has a right to see. FOIA request automation generates redacted copies that comply with public records requirements while protecting active investigations, witness identities, and victim information.

94%
Reduction in manual evidence review time via AI-powered analysis
NLP
Natural language semantic search across entire evidence corpus
Brady
Automatic flagging of potentially exculpatory material before redaction
Computer Vision Pipeline

The evidence analysis engine processes video at native frame rate using a multi-model inference pipeline: YOLOv8 for real-time object detection (faces, weapons, vehicles, license plates), DeepSORT for cross-frame object tracking (following a suspect across multiple camera angles), and CLIP for semantic understanding (enabling natural language queries against visual evidence). Face detection achieves 99.2% recall at 0.3% false positive rate; license plate recognition achieves 97.8% accuracy across plate types, lighting conditions, and angles; weapon detection classifies 12 weapon categories with 94.6% accuracy. All AI analysis results are logged as annotations linked to specific timestamps and frame numbers, with the AI model version and confidence score recorded in the custody chain. This ensures that any AI-generated finding can be independently verified or challenged by re-running the same model version against the cryptographically verified original evidence.

Brady-Integrated Redaction

The automated redaction engine operates under a constitutional constraint that distinguishes it from commercial redaction tools: it must not redact potentially exculpatory material that the prosecution is constitutionally required to disclose under Brady v. Maryland (1963) and Giglio v. United States (1972). Before any redaction is applied, the system runs a Brady/Giglio scan that analyzes the content for material that could be favorable to the defense — alibi evidence, witness credibility issues, alternative suspect indicators, or evidence of procedural violations. If Brady-relevant material is detected, the system flags it for ADA review before allowing redaction to proceed. This prevents the catastrophic scenario where automated redaction inadvertently destroys the defense's access to constitutionally protected evidence. Louisiana's Act No. 225 (2025) — the first state framework for AI evidence — reinforces the need for such safeguards as AI systems increasingly handle evidence that was traditionally reviewed exclusively by human prosecutors.

Engine 05–06
Prosecution Sharing · Retention & Disposition
Every disclosure logged. Every retention policy enforced. Every disposition defensible.

Engine 05 provides encrypted, watermarked, expiring evidence packages for prosecution-defense sharing. Each package carries recipient-specific forensic watermarks (invisible, surviving screenshot and re-encoding), AES-256 encryption, configurable expiration dates, and granular access controls — the DA can share body-cam footage with the public defender while preventing download, printing, or redistribution, with every viewing logged to both parties' custody chains. Engine 06 manages evidence lifecycle through policy-driven retention and disposition automation. Evidence retention periods vary by jurisdiction, case type, and disposition status — routine patrol video may be retained 60–90 days, while homicide evidence must be preserved indefinitely. The system enforces these policies automatically, generating disposition eligibility reports, requiring supervisory approval before any destruction, and maintaining permanent records of what was disposed, when, by whom, and under what authority. A sheriff's office deployment disposed 2.8 petabytes of eligible evidence without touching a single protected file, saving $1.8M annually in storage costs.

AES-256
End-to-end encryption for all evidence sharing with forensic watermarking
40%
Storage cost reduction through automated retention policy enforcement
2.8PB
Eligible evidence safely disposed at a single deployment site
Forensic Watermarking

Every evidence file shared through Engine 05 carries a recipient-specific forensic watermark that is invisible to the viewer, survives screenshot capture, video re-encoding, and format conversion, and uniquely identifies the recipient if the evidence is leaked or misused. The watermark is embedded at the pixel level using a spread-spectrum technique that distributes the watermark signal across the entire frame, making it robust against cropping, compression, and resolution changes. If leaked evidence appears online or in unauthorized hands, the watermark extraction process identifies the specific recipient whose copy was leaked — with a false identification rate below 0.001%. The watermarking system operates entirely within the custody chain: watermark embedding events are logged with the recipient's identity, the specific watermark signature, and the timestamp, ensuring that the watermark itself is part of the verifiable evidence provenance.

Disposition Compliance Architecture

The retention engine maintains a policy database covering 50+ jurisdictional frameworks (CJIS, FedRAMP, FOIA, GDPR, CCPA, state-specific statutes, and agency-specific policies) and applies the most restrictive applicable standard to each piece of evidence based on its jurisdiction, case type, and disposition status. When evidence becomes eligible for disposition, the system generates a disposition report listing every file, its retention category, the governing policy, and the calculated eligibility date. A supervisory review queue requires human approval before any destruction proceeds. The system enforces legal holds that override retention policies when active litigation, appeals, or innocence project reviews require preservation. Permanent audit records of all disposition actions are maintained in blockchain-anchored WORM storage, ensuring that decades later, an agency can demonstrate what evidence existed, when it was destroyed, under what authority, and that no protected evidence was affected.

Engine 07–08
Cross-Jurisdiction Collaboration · Evidence Analytics
Six agencies. Three states. One unified evidence workspace — provisioned in four hours

Engine 07 creates secure collaboration spaces where multiple agencies contribute and access evidence under their own compliance frameworks simultaneously. Data residency controls ensure that evidence subject to GDPR, CCPA, or national sovereignty requirements never physically leaves the required geographic boundary — even while being viewed by authorized personnel in another jurisdiction. Federated search allows investigators to query across agency boundaries without physically transferring files, and bilateral audit trails ensure that every agency maintains its own defensible custody record. Engine 08 transforms evidence management from a storage problem into a strategic intelligence function. Operational dashboards show real-time evidence volumes, ingestion rates, pending redaction queues, and approaching retention deadlines. Case intelligence analysis correlates evidence utilization patterns with case outcomes — revealing that cases where prosecutors accessed body-cam footage within 48 hours of arrest resulted in 23% higher conviction rates than those where footage was accessed after two weeks.

4hr
Time to provision unified multi-agency evidence workspace
GDPR+
Per-evidence-item data residency enforcement across jurisdictions
23%
Higher conviction rate when evidence accessed within 48 hours of arrest
Federated Evidence Architecture

The cross-jurisdiction engine uses a federated architecture where each agency maintains sovereign control over its evidence while enabling authorized cross-boundary access. When a multi-agency task force is formed, Vault provisions a unified evidence workspace by creating a virtual evidence repository that aggregates metadata indexes from each participating agency without physically moving any files. Investigators can search across all agencies' evidence using the same semantic search engine (Engine 03), but each query is executed locally on the source agency's infrastructure, with only the result metadata (timestamps, thumbnails, classification tags) returned to the requesting investigator. Full evidence files are accessed through encrypted, watermarked streams that maintain the source agency's custody chain while creating a parallel access record in the requesting agency's chain. The EU LAW-GAME project has validated this consortium architecture using Hyperledger Fabric, demonstrating that existing Digital Evidence Management Systems can integrate seamlessly via blockchain APIs without replacing their underlying infrastructure.

Evidence-to-Outcome Intelligence

The analytics engine correlates evidence management metrics with case outcomes across the entire evidence lifecycle, revealing operational insights that no manual review process can produce: evidence access latency (how quickly prosecutors review new evidence after capture); evidence breadth (how many evidence sources are reviewed per case type); evidence completeness (whether all available evidence from a scene was collected and ingested); and outcome correlation (whether cases with faster evidence access, broader evidence review, or more complete evidence collection achieve higher conviction rates, shorter time-to-disposition, or fewer appeals). A metropolitan deployment discovered that cases where prosecutors accessed body-cam footage within 48 hours resulted in 23% higher conviction rates and that early evidence access changed charging decisions in 31% of cases — enabling prosecutors to see what actually happened before making commitments they could not support at trial.