Bolstering Peers

Secure,  irreversible economic freedom is vital because it represents a basic  foundation and stepping stone to more comprehensive independence. Not  only can financial sovereignty give a passive avenue to resist a  government encroaching on personal freedom, but it can also give  individuals the opportunity to do the same within a domestic setting.

Satellite  coverage is an essential first step in ensuring sound, consistent and  borderless dispersal of Bitcoin participation. The utility provided by  having constant access to bitcoin blocks, with only a fifty dollar dish,  to a permissionless, off-grid payment rail is immense.

The  provision of free satellites and API's for data download are undoubtedly valuable for providing constant access to Bitcoin while also  dramatically decreasing the cost of running a node. Still,  looking through a critical lens surmises some reasonable vulnerabilities  that will hopefully be addressed by the greater Bitcoin community going  forward. Just because satellites largely represent a "last resort",  does not mean it should be reliant on a lesser security model than would  otherwise be acceptable.

Blockstream is currently renting  hosted space on a variety of satellites spread orbiting the world.  Because the satellites are not built for Blockstream, they act as relay  devices instead of full nodes, broadcasting blocks uplinked from ground stations to the other satellites as well and receiver dishes throughout  the world. With a dedicated satellite, Blockstream wouldn't have to use  ground stations but the financial burden of this is significant.

​In  the next few years, the world may see rural, low-bandwidth areas in underdeveloped regions integrate Bitcoin into the local economy by way  of receiving free blocks from mounted dishes, and then verifying and  proliferating around the blocks around a local mesh net. These economies may be solely reliant on blocks broadcasted by their regional satellite for connectivity to the main chain. This  means the local economy hinges on the validity and consistency of data  being uplinked from ground stations. Without access to the internet or  other satellites, on a whim, an economy can be partitioned from the network via an overreliance on a single peer. While  nobody could force individual nodes to accept blocks based off of  non-consensus rules, an eclipse attack remains a pronounced threat.

CubeSats

CubeSats  differ from larger, more permanent and powerful satellites and could  give the Bitcoin network additional security and fault tolerance. First,  CubeSats are customizable enough to run individual validating full  nodes from space. This means low bandwidth users without internet  connectivity could broadcast and receive blocks from a network of peers  in space rather than a single satellite. With a fleet of dedicated CubeSats, no ground stations or teleports are needed.

CubeSats  are relatively inexpensive and are often released into Low Earth Orbit (LEO) as secondary cargo. For power, CubeSats rely on a combination of  solar panels and built-in battery. While they are inexpensive, they can  also be unreliable and often fall out of Orbit in only a few months. Bitcoin Developer Jeff Garzik considered launching his own fleet of CubeSats but plans seem to have sputtered.

the #bitcoin satellite network is using leased bandwidth on 4 geostationary sats over 6 coverage zones. they are mixed use broadcasting TV &  industrial data etc. problem with cubesats is you either need lots of  them, or tracking dishes. also need BIG dishes because signal is weak— Adam Back (@adam3us) December 18, 2018

While CubeSats can  provide more peers than a larger constellation, they can't necessarily  provide as consistent of peers. CubeSats sit in LEO and are knocked down  and around by atmospheric conditions, requiring constant recalibration. Problems with this can be mitigated through being in the range of many  nodes or with a tracking dish. But even then, the low power of these  devices can make connectivity a challenge due to bandwidth constraints.

This  is addressed in a new Bitcoin proposal dubbed "Minisketch" focussed on dramatically reducing the bandwidth overhead associated with running a  Bitcoin full node by cutting down on the amount of redundant data being  broadcasted. Satellites are listed as one of the top applications in the Github seen below.

Geostationary CubeSats?

CubeSats  are improving rapidly and becoming cheaper as they reach economies of scale. If they were able to provide the same consistency as larger Geostationary Satellites, CubeSats could provide more reachable network  peers for off-grid users and thus more decentralization and security. Instead of an off-the-grid town being tolerant to only the failure of  one regional satellite, they could now connect to a series of local ones  as well, adding malevolent CubeSats to Jameson Lopp's dedicated bad node list.

CubeSats are launched into orbit with a solar panel and  battery, but if the device ever turns energy negative, it immediately  becomes space debris. The battery needs to be strong enough to  constantly last through periods of zero sunlight.

Securing New Value

Bolstering  security is necessary as new protocols begin to bootstrap bitcoin's security model for securing more than just transactions.

Microsofts  "sidetree", an open-source permissionless digital identity protocol,  plans on pinning user-owned digital identity to bitcoin transactions and  transacting public-key, distributed identifiers through HTLC channels  and around a dedicated sidechain mesh. Once again, this directly  affects off-grid users who often lack a sound, secure, or accessible  form of identification. Low-cost proof of identity can help give people  access to financial services and can even be incorporated into existing  government functions.

Another sidechain,  Lot49, is being developed to incentivize a mesh-net for communication  over GNU radio. As this project expands, communication networks can be  built by running Lot49 with local peers and settling on the global  Bitcoin chain for payment finality by broadcasting to a fully validating  CubeSat. Lot49 mesh will support applications like point of sale,  without an internet connection.

The additional  value relying on the Bitcoin network should be factored in when considering how Bitcoin's security model will adapt over time. The proliferation of a more robust satellite network including an fleet of fully validating CubeSat nodes would have a tremendous impact on both ease of participation and overall security. If the proposal for Minisketch is incorporated into Bitcoin, it would have a sizeable impact on the viability of CubeSats and protect low-bandwidth users from  eclipse attacks.

written by Francis