Problems with blockchain

A lot of hopes are placed on blockchain technology. They range from more modest aspirations, like ensuring secure food chains, to hyperbolic claims of creating economic and socio-political emancipation of humankind. Blockchain is said to offer a decentralised way of doing things while solving the problem of trust, which makes it very appealing for platform economy. What is often left out is the consideration of the negative consequences and the barriers to the wide adoption of the blockchain.

Negative consequences and barriers

The main negative impact on current implementations of blockchain relates to energy usage and consequential environmental and other impacts. Blockchains require a lot of computing power, which in turn requires a lot of electricity and cooling power. For example, for Bitcoin alone it has been calculated that by 2020 it might use as much energy as Denmark. While blockchain-based solutions – or cryptogovernance in general – has been offered as a way to alleviate some environmental problems by increasing traceability and ensuring ownership, the negative impact of these solutions to the environment should not be ignored.

The current architecture of the blockchain is high on energy consumption, and also has problems with scaling. The root problem is that all transactions in the blockchain have to be processed by basically everyone and everyone must have a copy of the global ledger. As the blockchain grows, more and more computing power and bandwidth are required and there is a risk of centralisation of decision making and validation power in the blockchain as only a few want to devote their efforts to keeping the blockchain running.

Along with problems of scaling, the issue of governance in blockchains is an unsolved challenge. Since there is no central actor, there needs to be mechanisms for solving disputes. The forking of The DAO and the discussions around it are a case in point. So while blockchain may offer new decentralised solutions to governance, the technology in itself is not enough.

Possible solutions

There are some solutions to the problem of scaling, such as increasing block size, sharding (breaking the global ledger into smaller pieces) and moving from proof of work consensus mechanism to proof of stake. One interesting solution that also decreases the computational power needed is Holochain. Instead of having a global ledger of transactions, in a holochain everyone has their own “blockchain”, and only the information needed to validate the chains is shared. This means basically that while a blockchain validates transactions with global consensus, a holochain validates people – or to be more precise, the authenticity of the chains of transactions people own.

Whatever the technological solution, a discussion on the negative consequences of blockchain is required to balance the hype. Do we want to implement blockchains everywhere no matter the environmental costs? What are the tradeoffs we are willing to make?

Selected articles and websites


Mikko Dufva

Research Scientist VTT Technical Research Centre of Finland Ltd
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