Blockchain interoperability survey

Vladan Lausevic
4 min readSep 1, 2020


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In May this year, a scientific article was published by Rafael Belchior, André Vasconcelos, Sérgio Guerreiro, Miguel Correia under the name A Survey on Blockchain Interoperability: Past, Present, and Future Trends. In this article, the researchers argue that blockchain interoperability is an emerging trend and one of the crucial features of blockchain technology, but that the knowledge necessary for achieving it is fragmented, which makes it challenging for academics and the industry to achieve interoperability among blockchains.

The article is based on analysis of 262 papers together with 70 grey literature documents. From the 332 documents, researchers have systematically analysed and discussed 80 documents and classified studies in three categories: Cryptocurrency-directed interoperability approaches, Blockchain Engines, and Blockchain Connectors. One of the main findings is that blockchain interoperability has a much broader spectrum than cryptocurrencies.

Furthermore, it is stated that blockchain systems still have a long way ahead to achieve mass adoption. One reason, according to this article is that serving and responding to the needs of different stakeholders is resulting in a need for various blockchain features and capabilities.

According to researchers, this is a motivating factor for the creation of different blockchains, leading to a more heterogeneous ecosystem but also lack of interoperability. It is also stated that both developers and researchers have to choose between novelty and stability, leading to a vast diversity of choices leading to fragmentation where there are many immature blockchain solutions which also are not interoperable.

From the article

The article is also focusing on aspects such as interactions between source blockchain and target blockchain, as when it comes to the cross-chain communication protocol (CCCP). The CCCP defines the process by which a pair of blockchains interact to synchronise cross-chain transactions correctly. It is also mentioned that the cross-blockchain communication protocol (CBCP) defines the process by which a pair of blockchains interact to synchronise cross-blockchain transactions correctly.

According to the researchers, the difference between CCCPs and CBCPs is significant because CCCPs typically can leverage the constructs and functionality of the interoperating blockchains, as by utilising smart contracts to implement a relay. While in contrast, the CBCPs normally require blockchains to be adapted.

From the article

The article also includes references such as to technical report from the National Institute of Standards and Technology that defines blockchain interoperability “a composition of distinguishable blockchain systems, each representing a unique distributed data ledger, where atomic transaction execution may span multiple heterogeneous blockchain systems, and where data recorded in one blockchain are reachable, verifiable, and referable by another possibly foreign transaction in a semantically compatible manner”.

Other references are stating that for example a registry for both public and private blockchains could be written in a public blockchain with strong security assumptions, which means a high degree of decentralisation.

From the article

The researchers are also writing about different types of blockchains and operating systems, such as when it comes to scalability and sidechains. In a larger part of their article, a number of different blockchains, organisations and systems is presented and analysed concerning research questions.

One example mentioned is the RSK federated sidechain and general-purpose smart contract platform pegged to the Bitcoin network that offers improvements in security and scalability of the latter. The RSK system takes approximately the time of 15 hours to confirm 100 Bitcoin blocks when converting BTC to RBTC20. To get RBTCs, a user has to send Bitcoin to a specific multi-signature address, meaning an address controlled by several parties, through the several signatures and located at the Bitcoin network. That address is controlled by the RSK Federation, which is composed of several stakeholders and where the federation members use hardware security modules.

Among the concluding parts of the article are conclusions that the first step towards blockchain interoperability is the creation of mechanisms allowing the exchange of tokens and cryptocurrencies. The researchers also argue that several blockchains can be considered as mature enough to support applications built on top of them.

Furthermore, when it comes to interoperability, it is stated that there is a need for blockchains to have the necessary infrastructure and facilitating technologies and that the production of standards technologies like decentralised identifiers, verifiable credentials, cross-blockchain communication protocols and the representation of blockchain smart contracts can foster the likelihood for blockchain interoperability standards and solutions, as they remove considerable barriers to blockchain interoperability.

For more information form this article, click on the following link for download.



Vladan Lausevic

I am active as a social and policy entrepreneur. SEEDS ambassador. Motto: I have no identity, I have only identities.

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