/ docs / source / whatis.rst
whatis.rst
  1  ******************
  2  What is Reticulum?
  3  ******************
  4  
  5  Reticulum is a cryptography-based networking stack for building both local and
  6  wide-area networks with readily available hardware, that can continue to operate
  7  under adverse conditions, such as extremely low bandwidth and very high latency.
  8  
  9  To understand the foundational philosophy and goals of this system, read the
 10  :ref:`Zen of Reticulum <zen>`.
 11  
 12  Reticulum allows you to build wide-area networks with off-the-shelf tools, and
 13  offers end-to-end encryption, forward secrecy, autoconfiguring cryptographically
 14  backed multi-hop transport, efficient addressing, unforgeable packet
 15  acknowledgements and more.
 16  
 17  From a users perspective, Reticulum allows the creation of applications that
 18  respect and empower the autonomy and sovereignty of communities and individuals.
 19  Reticulum enables secure digital communication that cannot be subjected to
 20  outside control, manipulation or censorship.
 21  
 22  Reticulum enables the construction of both small and potentially planetary-scale
 23  networks, without any need for hierarchical or bureaucratic structures to control
 24  or manage them, while ensuring individuals and communities full sovereignty
 25  over their own network segments.
 26  
 27  Reticulum is a **complete networking stack**, and does not need IP or higher
 28  layers, although it is easy to utilise IP (with TCP or UDP) as the underlying
 29  carrier for Reticulum. It is therefore trivial to tunnel Reticulum over the
 30  Internet or private IP networks. Reticulum is built directly on cryptographic
 31  principles, allowing resilience and stable functionality in open and trustless
 32  networks.
 33  
 34  No kernel modules or drivers are required. Reticulum can run completely in
 35  userland, and will run on practically any system that runs Python 3. Reticulum
 36  runs well even on small single-board computers like the Pi Zero.
 37  
 38  
 39  Current Status
 40  ==============
 41  All core protocol features are implemented and functioning, but additions will probably occur as
 42  real-world use is explored. The API and wire-format can be considered complete and stable, but
 43  could change if absolutely warranted.
 44  
 45  
 46  Reference Implementation
 47  ========================
 48  The Python code, for which this documentation is written, and known as the Reticulum Network Stack,
 49  is the Reference Implementation of Reticulum. The Reticulum Protocol is defined entirely
 50  and authoritatively by this reference implementation, and this manual. It is maintained by Mark Qvist,
 51  identified by the Reticulum Identity ``<bc7291552be7a58f361522990465165c>``.
 52  
 53  Compatibility with the Reticulum Protocol is defined as having full interoperability,
 54  and sufficient functional parity with this reference implementation. Any specific protocol
 55  implementation that achieves this is Reticulum. Any that does not is not Reticulum.
 56  
 57  The reference implementation is licensed under the :ref:`Reticulum License <license>`.
 58  
 59  The Reticulum Protocol was dedicated to the Public Domain in 2016.
 60  
 61  
 62  What does Reticulum Offer?
 63  ==========================
 64  
 65  * Coordination-less globally unique addressing and identification
 66  
 67  * Fully self-configuring multi-hop routing over heterogeneous carriers
 68  
 69  * Flexible scalability over heterogeneous topologies
 70  
 71    * Reticulum can carry data over any mixture of physical mediums and topologies
 72  
 73    * Low-bandwidth networks can co-exist and interoperate with large, high-bandwidth networks
 74  
 75  * Initiator anonymity, communicate without revealing your identity
 76  
 77    * Reticulum does not include source addresses on any packets
 78  
 79  * Asymmetric X25519 encryption and Ed25519 signatures as a basis for all communication
 80  
 81    * The foundational Reticulum Identity Keys are 512-bit Elliptic Curve keysets
 82  
 83  * Forward Secrecy is available for all communication types, both for single packets and over links
 84  
 85  * Reticulum uses the following format for encrypted tokens:
 86  
 87    * Ephemeral per-packet and link keys and derived from an ECDH key exchange on Curve25519
 88  
 89    * AES-256 in CBC mode with PKCS7 padding
 90  
 91    * HMAC using SHA256 for authentication
 92  
 93    * IVs are generated through os.urandom()
 94  
 95  * Unforgeable packet delivery confirmations
 96  
 97  * Flexible and extensible interface system
 98  
 99    * Reticulum includes a large variety of built-in interface types
100  
101    * Ability to load and utilise custom user- or community-supplied interface types
102  
103    * Easily create your own custom interfaces for communicating over anything
104  
105  * Authentication and virtual network segmentation on all supported interface types
106  
107  * An intuitive and easy-to-use API
108  
109    * Simpler and easier to use than sockets APIs and simpler, but more powerful
110  
111    * Makes building distributed and decentralised applications much simpler
112  
113  * Reliable and efficient transfer of arbitrary amounts of data
114  
115    * Reticulum can handle a few bytes of data or files of many gigabytes
116  
117    * Sequencing, compression, transfer coordination and checksumming are automatic
118  
119    * The API is very easy to use, and provides transfer progress
120  
121  * Lightweight, flexible and expandable Request/Response mechanism
122  
123  * Efficient link establishment
124  
125    * Total cost of setting up an encrypted and verified link is only 3 packets, totalling 297 bytes
126  
127    * Low cost of keeping links open at only 0.44 bits per second
128  
129  * Reliable sequential delivery with Channel and Buffer mechanisms
130  
131  
132  Where can Reticulum be Used?
133  ============================
134  Over practically any medium that can support at least a half-duplex channel
135  with greater throughput than 5 bits per second, and an MTU of 500 bytes. Data radios,
136  modems, LoRa radios, serial lines, AX.25 TNCs, amateur radio digital modes,
137  ad-hoc WiFi, free-space optical links and similar systems are all examples
138  of the types of interfaces Reticulum was designed for.
139  
140  An open-source LoRa-based interface called `RNode <https://unsigned.io/rnode>`_
141  has been designed as an example transceiver that is very suitable for
142  Reticulum. It is possible to build it yourself, to transform a common LoRa
143  development board into one, or it can be purchased as a complete transceiver
144  from various vendors.
145  
146  Reticulum can also be encapsulated over existing IP networks, so there's
147  nothing stopping you from using it over wired Ethernet or your local WiFi
148  network, where it'll work just as well. In fact, one of the strengths of
149  Reticulum is how easily it allows you to connect different mediums into a
150  self-configuring, resilient and encrypted mesh.
151  
152  As an example, it's possible to set up a Raspberry Pi connected to both a
153  LoRa radio, a packet radio TNC and a WiFi network. Once the interfaces are
154  added, Reticulum will take care of the rest, and any device on the WiFi
155  network can communicate with nodes on the LoRa and packet radio sides of the
156  network, and vice versa.
157  
158  Interface Types and Devices
159  ===========================
160  Reticulum implements a range of generalised interface types that covers the communications hardware that Reticulum can run over. If your hardware is not supported, it's simple to :ref:`implement an interface class<example-custominterface>`. Currently, Reticulum can use the following devices and communication mediums:
161  
162  * Any Ethernet device
163  
164    * WiFi devices
165  
166    * Wired Ethernet devices
167  
168    * Fibre-optic transceivers
169  
170    * Data radios with Ethernet ports
171  
172  * LoRa using `RNode <https://unsigned.io/rnode>`_
173  
174    * Can be installed on `many popular LoRa boards <https://github.com/markqvist/rnodeconfigutil#supported-devices>`_
175  
176    * Can be purchased as a `ready to use transceiver <https://unsigned.io/rnode>`_
177  
178  * Packet Radio TNCs, such as `OpenModem <https://unsigned.io/openmodem>`_
179  
180    * Any packet radio TNC in KISS mode
181  
182    * Ideal for VHF and UHF radio
183  
184  * Any device with a serial port
185  
186  * The I2P network
187  
188  * TCP over IP networks
189  
190  * UDP over IP networks
191  
192  * Anything you can connect via stdio
193  
194    * Reticulum can use external programs and pipes as interfaces
195  
196    * This can be used to easily hack in virtual interfaces
197  
198    * Or to quickly create interfaces with custom hardware
199  
200  * Anything else using :ref:`custom interface modules<interfaces-custom>` written in Python
201  
202  For a full list and more details, see the :ref:`Supported Interfaces<interfaces-main>` chapter.
203