PkBlock

PkBlock is a data structure and protocol designed for organizing and validating public-key information within block-oriented logs. It provides a compact, tamper-evident container for batches of public-key records, enabling efficient verification of key material and its associated certificates.

Typically, a PkBlock consists of a header and a list of records. The header may include a version identifier, a timestamp, a block index, and a cryptographic hash of the previous block to form a chain. Each record contains a public key, an associated certificate or certificate-like payload, a signature from a trusted authority, a validity period, and optional metadata such as identity assertions or usage constraints. Blocks can be linked via hash pointers, creating an append-only sequence that supports integrity checks and auditability.

PkBlock supports two common modes of verification. In a straightforward mode, verifiers check that each record’s certificate is valid at the stated time and that the block’s hash chain is unbroken. In a batch verification mode, a merkle-tree or similar accumulator summarizes the records, enabling fast proofs of inclusion for specific keys or certificates without exposing the entire block contents.

Applications for PkBlock include certificate transparency-like systems, distributed identity management, and large-scale PKI auditing in organizations or blockchain-enabled ecosystems. It is designed to complement existing PKI mechanisms by enhancing append-only logging, incremental verification, and dispute resolution.

Security considerations center on proper key management, trust anchor policies, and protection of block integrity against tampering or replay. Some deployments also address privacy concerns by controlling exposure of identity attributes within records.