Ledger-Anchored Validation Receipts (LAVR): Minimal Cryptographic Proof of Enforcement

Abstract

Abstract Existing accountability mechanisms based on audit logs, blockchains, and distributed ledgers attempt to prove compliance by recording what happened—transactions, identities, timestamps, or state transitions. While tamper-resistant, these approaches inherently generate behavioural traces that conflict with data-minimisation requirements and enable correlation, profiling, and surveillance. This creates a structural accountability–privacy paradox in modern regulatory frameworks such as the GDPR, which simultaneously require demonstrable compliance (Art. 5(2)) and strict limitation of personal data collection (Art. 5(1)(c)). This paper introduces Ledger-Anchored Validation Receipts (LAVR), a cryptographic mechanism that resolves this paradox by proving that enforcement occurred, rather than recording the underlying activity. LAVR operates exclusively at system finality boundaries—points where actions become irreversible, such as database commits, cross-border data exports, AI output release, payment settlement, or content publication. At each finality point, a hardware-adjacent enforcement gate evaluates a regulatory validation predicate derived from applicable legal constraints. Upon decision (Allow or Deny), the gate generates a minimal, fixed-size receipt that contains only enforcement metadata and explicitly excludes payloads, identities, transaction details, routing information, and fine-grained timestamps. The operational workflow consists of four steps: (1) an execution request reaches a finality boundary; (2) a trusted validation context evaluates scope, purpose, and control predicates; (3) a non-identifying receipt is cryptographically generated; and (4) a hash commitment of the receipt is anchored to a tamper-evident ledger. Unlike blockchain transaction logs, the ledger anchors only receipt commitments—not events—preventing the formation of transaction graphs or behavioural histories. Implemented using commodity hardware primitives (Trusted Execution Environments, SmartNICs, secure elements, and kernel-level finality hooks), LAVR enables accountability without surveillance across GDPR, AI Act, eIDAS, CBDC, NIS2, and Democracy Shield contexts. The approach demonstrates that regulatory simplification and stronger enforcement can be achieved through execution-time cryptographic proof rather than expanded monitoring or deregulation.