DEJor

DEJor is a distributed software framework for edge computing that provides verifiable, append-only logs and coordinated task execution across a network of edge devices. It aims to ensure data integrity, auditability, and resilience in environments with intermittent connectivity and heterogeneous hardware. DEJor combines a ledger-like data store with an orchestration layer to coordinate jobs, synchronize state, and maintain a tamper-evident history of events.

The project was proposed by researchers from multiple institutions in 2019 and released publicly as open-source in 2020. Version 1.0 followed in 2022, introducing a formal ledger model and a pluggable consensus interface. Since then, DEJor has seen pilot use in industrial IoT, logistics, and energy management.

Core components include Edge Nodes that collect data and execute tasks, Rendezvous Servers that help coordinate state without exposing the entire network, and a Ledger Engine that stores verifiable events. The system uses cryptographic signatures, Merkle trees, and a lightweight consensus protocol designed for constrained devices. It provides REST and streaming APIs and supports offline operation with secure synchronization when connectivity returns.

Security and governance: Data integrity is ensured through signed events and an append-only ledger. Access control uses role-based policies and per-node keys. The project maintains documentation and governance guidelines through its repository and community forums.

Applications and limitations: DEJor is applied in supply chains, smart grids, and industrial automation to improve traceability and fault diagnosis. Limitations include computational overhead on small devices and the need for careful key management and policy configuration.

See also distributed ledger technology and edge computing.