accdere

accdere is a hypothetical open specification for secure access control in distributed systems. It seeks to provide fine-grained, revocable authorization by combining capability-based security with cryptographic proofs, allowing resources to be accessed only when a valid capability is presented and verifiably authorized.

The name accdere draws from a stylized form of accedere, Latin for "to approach" or "to access," and is used by a community of researchers and practitioners proposing a portable model of authorization across domains.

Architecturally, accdere comprises the core protocol, capability tokens (CTokens), a policy ledger, and verifier libraries. A resource owner issues short-lived CTokens that encode the permitted operations, scope, and expiration. A client presents a CTOKEN to a resource server, which validates it against the policy ledger and the owner's public keys, potentially using cryptographic proofs to avoid disclosing unnecessary data. Revocation is supported through limited lifetimes and active revocation mechanisms. In some configurations, verifiers may operate offline with pre-distributed keys, while online checks ensure up-to-date revocation status.

Security and privacy considerations emphasize formal verification and minimal disclosure. The design encourages verifiable credentials and zero-knowledge approaches to reduce leakage while maintaining auditability.

Applications include cloud storage and API access, IoT and edge computing, and controlled data sharing in healthcare and finance. As a research proposal and emerging standard, accdere continues to be explored for interoperability with existing identity and access management systems, with debates about scalability, tooling, and cross-domain governance.

See also: Access control, Capability-based security, Verifiable credentials, Zero-knowledge proofs.