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Exonum Roadmap

Exonum roadmap represents the major functionality points our team is planning to bring to the product. Most of the features mentioned in this roadmap will be implemented for both Exonum Core and Java Binding. However, keep in mind that there will be a certain time interval between the availability of new features in Core and Java Binding with some latency for the latter.

Stay tuned for news about updates to the Exonum platform in our Medium blog.


This document is provided for informational purposes only. It is subject to changes at any time without specific notifications and approvals.

Fourth Quarter of 2018

Separation of Transactions and Messages

The separation of transactions and messages into two individual entities will lay the foundation for other crucial features such as standardization of interfaces of services, communication between services within the blockchain and other. This separation will also prove extremely useful in the efforts of changing the serialization format of Exonum to a more common one.

Protobuf as the Serialization Format in Exonum

Protobuf is the industry accepted serialization format supported in multiple programming languages. Use of Protobuf will ease the integration of Exonum with applications in other languages. It will also enable the development of light clients in other languages with less effort required.

Protobuf has already been used in several applications of Exonum Java Binding.

First Quarter of 2019

Secure Storage for Private Keys of the Node

A separate and secured storage for private keys of the nodes will enhance the safety of the system. Even in the case of unauthorized users gaining access to a node, they will not have access to its private key and will not be able to intervene into the consensus process.

Java Binding: Protobuf Support and Separation of Transactions and Messages

As we develop Java Binding alongside with Exonum Core, to equalize their functionality it is required to implement Protobuf support and separate the transactions and messages for Java Binding too. This step will promote all the corresponding benefits discussed above.

Java Binding: Time Service

We add another built-in Exonum service into the array of services that can be easily launched with an Exonum blockchain in Java – the Time Oracle. The Time Oracle allows user services to access the calendar time that validators supply to the blockchain.

Second Quarter of 2019

Secure Workflow for Node Administration

The introduction of a workflow for administrative operations, such as the deployment of services, is aimed at improving the security of the system. The exact details of the workflow are being currently discussed. One of the promising ideas is devising a service through which all the administrative processes will be conducted.

Exonum MerkleDB - Minimal Profile

The first step within the global initiative to introduce MerkleDB in Exonum. This step will result in implementation of a more intuitive storage API interface. Such interface will simplify interaction with the storage for service developers.

Java Application Package

This usability achievement allows shipping Exonum as a ready-to-install application package. The package is targeted at Java developers who plan to develop Exonum-based services. The application will have Rust and other related libraries pre-installed. This means that no compilation of the application will be required.

Java Light Client

With this step we expand the range of clients available for the framework. Apart from the light client library in JavaScript, we add a light client in Java – one of the most popular programming languages. Java client allows to send transaction of both Rust and Java services into the blockchain. It also supports functionality of the blockchain explorer available in Exonum. Namely, it allows to obtain information on blocks, transactions, network nodes (a number of transactions in pool, Exonum version, etc.).

Multiple Java Services

We enable support of several client services written in Java within one Exonum instance. The necessary set of services should be activated together with initialization of the blockchain. This feature serves as a prerequisite for dynamic Java services that will be implemented further.

Java Benchmarking

Collection of metrics that allow to monitor efficiency of the Java Binding tool in the frame of the application; also to make application profiling and determine its weak spots.

Third Quarter of 2019

Base for Dynamic Services

The executable file of Exonum instance contains a number of built-in services. Initially, developers launched the required services at the start of the network without further possibility to adjust the list of applied services. The present milestone provides an opportunity to turn on/off the services present in the executable Exonum file without restarting the network.

Fourth Quarter of 2019

Service Migration

An extension to the above-mentioned functionality on dynamic services. The service migration will enable a smooth update to new versions of the services, running in the blockchain, without service data loss.

New Storage API Support in Java

Following implementation of MerkleDB in Exonum Core, the Java Binding tool will also have to update its storage API to make it compatible with MerkleDB.

Java Light Client Enhancements

A full-fledged version of Java light client featuring support of cryptographic proofs of availability/absence of certain data in the blockchain.

Dynamic Java Services

The introduction of dynamic Java services will enable adding Java services to a running blockchain without the need to restart nodes. In other words, new services will be included into the network on the go.

First Quarter of 2020

Save Points and Old Blocks Clean-up

Introduction of save points, which are snapshots of the blockchain at a certain moment in time, will let a node quickly catch up with the rest of the network in case of downtime.

This feature is also considered as a basis to solve the problem of storing the blockchain when its history becomes to long and space-consuming.

Second Quarter of 2020

Exonum MerkleDB - Full-fledged Implementation

In the final implementation of this functionality the nested data collections stored in Exonum will receive a hierarchical pattern. The hierarchy of the Merkelized collections will allow to implement proofs of availability of the whole collections or their leaves in the blockchain. A user-friendly API of the Exonum MerkleDB will serve this purpose.

Communication between Services within the Blockchain

As a method of improving the modularity of services and expanding the possibilities for their reuse, we will introduce the ability for services to communicate with one another within one blockchain. Services will be able to issue and process transactions from other services and can, thus, be reused in a variety of scenarios.

As you may have noticed, the new features are to be released quarterly. You are welcome to contribute to Exonum development and improvement (see our contribution policy). For any questions on the upcoming implementations feel free to contact us in Gitter or Reddit.