Skip to content

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 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.

Storage Enhancements

We are planning to make Exonum storage interfaces more developer-friendly and, due to this optimization, improve system performance and data auditability. The first stage of storage improvements will include the separation of node-specific and consensus-related data, which may, for example, accelerate the node recovery process. Within this stage we will also implement a basic form of Storage API for services and external clients. Further improvements to storage will be introduced in one of the following versions.

Services Interface Standard

To change the way services are defined in Exonum, we will introduce a uniform service interface description, processed by means of Protobuf. Services will be described in a language-independent manner, according to a template which will, for example, simplify definition of transactions, their arguments, etc.

Uniform service definition will also ease the development of light clients in any language supported by Protobuf. In the first phase of the implementation, service interfaces will support a single method type – transactions. Other method types will be added in one of the following versions.

Service Identification

We plan on implementing a more logical mechanism of service identification in Exonum. Such a solution will ease the communication between services and external clients. This mechanism will also lay the foundation for the implementation of dynamic services.

Within the scope of implementing the service identification mechanism, we also plan to provide a uniform framework for installing external services in Exonum blockchains.

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.

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.

First Quarter of 2019

Service Interface Standard: Read Requests

To increase the performance of the system, we will add read requests to the list of methods supported by interfaces of services. Read requests do not modify the blockchain state and can be handled locally on the full node which receives the request from a client.

Pre-check of Transactions in the Memory Pool

Checking the validity of transactions which are included into the memory pool is one of the methods for preventing DoS attacks. This check will also ensure that transactions do not lead to any errors when processed.

Second Quarter of 2019

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. Support for dependencies between dynamic services will be added in one of the following versions.

Communication between Services within the Blockchain

As a method of improving the modularity of services and expanding the possibilities for their reuse, the Exonum team 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.

Storage Enhancements: Proofs and Storage API Improvements

As the next stage of improvements to the Exonum storage, we will add support for proofs in storage and in Storage API for external clients in particular. As for Storage API for services, it will include access control mechanisms and support for other metadata.

Third Quarter of 2019

Service Migration

Service migration will enable a smooth update to new versions of the services running in the blockchain, thus, making use of improvements, which the older versions do not provide.

DoS Resistance

The resistance of Exonum blockchains to several types of DoS attacks will further enhance the security of the system by defining the amount of memory a node can consume at any moment of time. We are working on improving the consensus mechanism to limit the number of consensus messages and unconfirmed transactions which a node needs to store at any given time.

Save Points

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. It is highly probable that this feature will be based on check points in RocksDB, the database currently used in Exonum.

Java Light Client

Exonum already features a light client library in JavaScript. We wish to expand the range of clients available for the framework and will add a light client in Java – one of the most popular programming languages.

Fourth Quarter of 2019

Dynamic Java Services: Dependencies

To expand the feature of dynamic Java services in Exonum, we will add the support for dependencies between services. Dependencies will be specified during service installation or initialization. Services will be able to process transactions issued by other services, in this way broadening and extending the functionality of one another.

Private Transactions

The functionality of private transactions implements the existence of certain data within the blockchain network which are known only to certain validators. These validators will execute private transactions locally, without changing the blockchain state.

Non-replayability of Transactions

Making sure that a certain transaction has not been conducted in the past will no longer require storing the whole blockchain history.

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.