append-only logs

Append-only logs are basically arrays you can only append to. If you think about it in terms of normal array operations, it is a log where you can only call get (index), push (data) and retrieve the log length, but where you can never overwrite old entries.
Using append-only logs, Hypercore can easily generate compressed bitfields describing which portions of a log a peer has. This, among other things, helps make the replication protocol light and efficient.

atomic batch insertions

A process for inserting multiple data items into a database in a single operation, ensuring that either all of the items are inserted or none of them are.


A self-balancing tree data structure that is used to store data in a sorted and searchable manner.


A decentralized file-sharing protocol that allows users to download and share files directly with each other, rather than downloading them from a central server.


A device or computer that requests data or services from a server.


The process of converting encrypted data back into its original form.

DHT (Distributed Hash Table)

A decentralized data structure that is used to store and retrieve data over a network. The HyperDHT is used to facilitate the discovery of peers and to enable connections between them.


The process of comparing two data sets to identify their differences.

discovery key

A unique identifier that is used to identify a Hypercore and to discover other peers that have replicas of the same Hypercore.


The process of converting data into a coded form that can only be accessed or decrypted by someone who has the appropriate key or password.

end-to-end (E2E)

A type of communication or networking in which data is transmitted directly between the sender and the recipient, without passing through any intermediaries.


A technique for establishing connections between peers behind firewalls or NATs (Network Address Translators) by sending packets to a mediating server that helps establish the connection.

key/value store

A database that stores data in the form of key/value pairs, where each key is unique and is associated with a specific value.

merkle tree

A tree-like data structure that is used to verify the integrity of data by generating a hash of the data and storing it in a tree-like structure.


A container for a set of identifiers, such as variables or functions, that is used to prevent naming conflicts and to organize code.


The process of connecting devices or computers together for the purpose of communication or data exchange.


A computer or device that is connected to a network and able to communicate with other peers.

peer-to-peer (P2P)

A type of communication or networking in which each device or computer acts as both a client and a server, allowing for direct communication between devices without the need for a central server.


A set of rules or standards that govern the format and content of data transmitted over a network.

random-access storage

A type of storage that allows for fast and efficient access to any part of the stored data, regardless of its location.


A device or computer that provides data or services to clients.


A period of time during which a user interacts with a computer or device.

sorted iterator

An iterator that returns the elements of a data structure in sorted order.


A subject or theme that is being announced or shared by a group of peers.

UDP (User Datagram Protocol)

A protocol for sending data across a network that is designed to be fast and efficient. In Hyperswarm, UDP is used as the underlying protocol for hole-punching, which is a technique for establishing connections between peers behind firewalls or NATs.