An Introduction to Holochain: Concept, Architecture, and DHTs

Holochain is a git (free and open source distributed version control system) that does not require Proof of Work (PoW) and Proof of Stake (PoS). It is based on the DHT (distributed hash table) protocol utilized by BitTorrent for data lookup and file sharing.

The Concept

Holochain was conceived and developed as a decentralized progression from blockchain. It is designed to embody and support social coherence based on a set of agreements for reliable data and value sharing. Holochain transcends high computational overhead for consensus achievement, which eliminates unnecessary Pareto Principle effects. 

Holochain is a git (free and open source distributed version control system) that does not require Proof of Work (PoW) and Proof of Stake (PoS). It is based on the DHT (distributed sloppy hash table) protocol utilized by BitTorrent for data lookup and file sharing. However, holochain implementation is also peer validating, sharded (horizontally partitioned), and centered around a monotonic distributed hash table. Each node operates its own source chain that can be shared to a mass-distributed git repository.

Subsystemic Architecture

Holochain is composed of three primary sub-systems:

Application (Nucleus)

• Connected to a web browser for user interface, the nucleus unifies the entire holochain ecosystem. It reads and writes on the local source hash chain while inputting or extracting data via the shared DHT confirmed by common nodal rules and projections.

Local Chain

• In the holochain ecosystem, each participant owns a local chain for item signing prior to shared DHT publication. Multi-party interactions (e.g., currency transfer between two people) are signed by each participant, committed to their respective chains, and mutually shared to the DHT.

Shared Storage (Validating DHT)

• In holochain DHT systems, data content is addressed via cryptographic hash, so unaltered data reception is confirmed via self-hashing. When validating DHT, the provenance of each data bit is confirmed; thus validating author signatures and local chain commitments. Holochain allows meta-data to join DHT data for information publication about a person or node (transactions, top of hash chain) as well as a data element (tags, comments, ratings).

Within each subsystem, there exist two holochain participation modalities- chain author and DHT node:

Local chain authorship – Your chain is a signed, sequential record of the data you create and share on the holochain. Depending on the holochain’s validation rules, this data may be immutable and non-repudiable. Your local chain/data storage pattern is as follows:

1. Validates your new data
2. Stores the data in a new chain entry
3. Signs the data to your chain
4. Indexes the content
5. Shares the data to the DHT
6. Responds to validation requests from DHT nodes

DHT node validation and publication – Your node receives a request from another node to publish DHT data. It validates signatures, chain links, and other application-specific data of the publishing source chain.

Each modality may be run in a separate container, which communicates via network interface. Holochain is powered by holographic data, which quantifies blockchain security and information quality within shared information system designs and processes:

'Holochain’s core takes an agent-centric view of data, with user autonomy built directly into its architecture and protocols. Since data is really about remembering our lived and shared experiences (warm data), and governance is about recognizing and evolving our mission and processes through those experiences, distributing the storage and processing of that data fundamentally changes how we coordinate and interact with each other. -Collaborative Governance Technologies

(Originally published here)