Compliance Deep Dive

Risk scoring, sanctions screening, Travel Rule, wallet verification, and audit.

Risk Scoring

Every transaction is scored against 7 rules:

Rule	Trigger	Severity	Score
`THRESHOLD_10K`	>= $10,000	Medium	+15%
`THRESHOLD_50K`	>= $50,000	High	+30%
`VELOCITY_24H`	15+ tx in 24h	Medium	+10%
`VELOCITY_1H`	30+ tx in 24h	High	+25%
`NEW_WALLET`	First transaction	Low	+5%
`ROUND_AMOUNT`	$5,000+ increments	Medium	+5%
`SELF_TRANSFER`	sender == receiver	Low	+10%

Decision engine:

< 30% = approved (auto-execute)
30-50% = flagged (requires user confirmation)
>= 50% = blocked (automatic rejection)

Fast-track: transactions under $500 skip most checks (only self-transfer check).

Sanctions Screening

NautLense screens against 4 sanctions lists:

List	Source	Entities
OFAC SDN	US Treasury	16,910+
SECO	Swiss SECO	Swiss sanctions
EU	European Union	EU consolidated list
UN	United Nations	UN Security Council

Screening methods:

Name matching with fuzzy tolerance
Address matching (exact, for crypto addresses like Tornado Cash)
Batch screening up to 100 entities per request

Travel Rule (FATF Recommendation 16)

Supported Jurisdictions

Code	Regulator	Threshold	Self-Hosted Wallet
CH	FINMA	0 CHF (all transfers)	Verify all amounts
DE	BaFin	0 EUR	Verify > 1,000 EUR
AT	FMA	0 EUR	Verify > 1,000 EUR
EU	National FIU	0 EUR	Verify > 1,000 EUR

Required Originator Fields

Switzerland (CH): name + account + one of: address / (dob+pob) / national_id / customer_id
Germany (DE): name + dlt_address + account + one of: (address+document_number+customer_id) / (dob+pob)
Austria (AT): name + address + dob + nationality + account (strictest — all mandatory, no alternatives)
EU Generic: Same as Germany

Data Completeness Scoring

completeness = presentFields / totalFields

1.0  = compliant (all required fields present)
< 1.0 = missing_info (with list of missing fields)

Wallet Verification (Poco)

Cryptographic proof of wallet ownership, ported from production NautPoco system.

Signature Challenge Flow

POST /wallets/verify/initiate — generates challenge with 5-word slug + nonce + 30-min expiry
Client signs challenge using wallet private key (ed25519 for Solana, secp256k1 for EVM)
POST /wallets/verify/confirm — NautLense verifies cryptographic signature
Verification valid for 1 year

Challenge Message Format

NautLense Wallet Verification
Wallet: 7xKXtg2CW87d97TXJSDpbD5jBkheTqA83TZRuJosgAsU
Challenge: brave-purple-dolphin-happy-sunset
Nonce: a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6
Timestamp: 2026-03-27T14:30:00.000Z

Solana Off-Chain Message Format

Header: \xff + "solana offchain" + \x00\x00
Length: 2-byte little-endian (message UTF-8 byte length)
Body:   UTF-8 encoded challenge message

Verified using nacl.sign.detached.verify()with the wallet's ed25519 public key.

Emergency Lockdown

In-memory flag for zero-latency enforcement (no DB round-trip)
Database persistence across server restarts
HTTP 423 Locked response on all /tx/capture calls
Blocked transaction count tracked during lockdown
Audit trail of all lockdown events

SAR Reports

Case numbers: SAR-YYYY-NNNN format
Authority filing workflow with sign-off
Asset freeze capability on submission
Linked to transactions and wallet profiles

Audit Trail

SHA256 hash chain across all captured transactions:

Each record contains hash (SHA256 of record + prev_hash) and prev_hash
GET /tx/verify-chain walks the entire chain
Any tampering breaks the chain at the modified record
Critical notification generated on chain break