The document discusses the concept of a general-purpose blockchain platform that can implement various blockchain systems with revisable settings, unlike existing blockchains that are fixed to a specific implementation. It provides examples of how such a platform could use different consensus algorithms, pruning methods for data storage, and state tree structures. The document also contrasts this concept with existing blockchains like Bitcoin and Ethereum that have currency systems tightly coupled with the blockchain implementation. A general-purpose platform may help decouple the blockchain from applications and allow one platform to support multiple interacting applications and cryptocurrencies.

1. Agora: general-purpose blockchain
platform
Yuki Washida
AIH software
March 26, 2016

2. general-purpose blockchain platform
not a program that runs a blockchain system of a fixed specification, but a platform to
implement various blockchain systems of revisable settings.
example
use various well-known hash functions.
adopt POW, POS, POW/POS hybrid etc.
leverage Bitcoin-like mining scheme, Ethereum-like mining scheme, etc.
persistence mechanism of blockchain.
retain all data.
delete unnecessary data (pruning).
construct a state tree and delete all data that is sufficiently old.
does not save all data (does not retain data in the platform layer but in the application
layer if necessary).
create diverse state trees.
2 / 9

3. general-purpose blockchain platform
so far
Bitcoin
a distributed cryptocurrency on top of a blockchain.
is not a general-purpose system per se.
in fact, in the reference implementation, the implementation of blockchain part and
that of cryptocurrency-specific part is entangled together. namely, the implementation
of blockchain in the Bitcoin reference implementation is FOR USE ONLY IN Bitcoin.
Bitcoin 2.0
generalization and other functions than currency underpinning the application layer.
Ethereum・・・in order to build various kinds of applications that employ the blockchain
technology, it allows a transaction to be interpreted as a Turing-complete program and
executed as such. It is also closely tied to a currency system.
covers Bitcoin with a generalization layer and the application layer is mounted thereon.
Counterparty・・・it allows a Bitcoin transaction to be interpreted as a Turing-complete
program in the meta-level.
3 / 9

4. general-purpose blockchain platform
the future
decoupling between blockchain and application part.
roll-sharing between system and application programmers.
the relationship between blockchain systems and applications is not one-to-one. that
is one-to-many in nature.
4 / 9

5. general-purpose blockchain platform
so far
tandems between multiple cryptocurrencies are rare and minor.
Bitcoin is a distinct autonomous system. Litecoin is another distinct autonomous
system. Ethereum...
exception
merged mining
share mining resource.
Bitcoin and Namecoin.
uncommon.
5 / 9

6. general-purpose blockchain platform
the future
tandems between multiple cryptocurrencies will be the next trend.
sidechain
a framework to transact arbitrary types of cryptocurrencies in any cryptocurrency network.
a blockchain stores arbitrary types of cryptocurrency transactions.
must support multiple cryptocurrency protocols.
tandems between cryptocurrencies and the other types of blockchain applications or among
such applications may be burgeoning out.
therefore
it is arguably easy to coordinate applications built on top of the same platform.
conversely, due to the easiness of coordination and cooperation, it is probable that different
blockchain applications will interact with each other more collaboratively and the blochchain
ecosystem may be increasingly thriving.
6 / 9

7. basic feature
blockchain
major hash functions
POW
POS
parent block selection policies
persistence
state trees
P2P communication
building blocks of basic applications
cryptocurrency, cryptoshare, cryptobond...
data management features
smart contracts
7 / 9

8. extensibility
extensibility is necessary to support building applications that need extra features
beyond built-in ones.
interface for extensibility.
extend built-in features or conception via this interface.
8 / 9

9. blockchain settings file
a file that specifies settings of a blockchain system.
the platform runs the blockchain system based on the settings in the file.
9 / 9