Compacting a 290GB Bitcoin Blockchain size into Kilobytes! What Utreexo can Achieve

July 30, 2020 Off By Ayobami Abiola

Believe it or not, there is no cryptocurrency that will ever take the place of Bitcoin in achievements and in the hearts of hodlers. Each new innovation can only seek to make its own unique impact while trying to make amends where BTC failed. In mining, there has been enough research which reveals that Bitcoin is quite centralized as only people who have powerful machines and stay in areas with low energy cost can profit from it. 

Bitcoin Halving and lone Miners

The Bitcoin network saw a lot of withdrawal of lone miners after its block halving this year because mining is no more profitable for them. These miners have to divert their mining power to mine alternate cryptocurrencies like Digibyte because it resists mining centralization. Digibyte can be mined with less powerful hardware as its algorithm resists mining by powerful machines.

The Blockchain Size

Another inherent weakness of the Bitcoin network is that new nodes that want to connect to the network must download all the blockchain data which is approximately 290GB. This is a lot of disk space that requires an SSD and not an HDD. For wallets or nodes that want to run their services or connect to the blockchain, the size is a huge barrier which is cost implicating. 

Dealing with the Blockchain Size is the reason why light wallets were introduced. These wallets do not need to download the whole blockchain to operate, they connect with a specific node to service them. For some wallets, there is the option of which node to connect to, for others there is only one. What happens is that light wallets only request or use the block identifiers (Block headers) to determine the balance of any account. Since block headers are smaller in size, light wallets do not need to accumulate too much size. 


Because of the ways light wallets request and send data to the blockchain, there are security risks attached that are not faced by full nodes. According to Tadge Dryja from MIT Media Lab Digital Currency Initiative (MIT DCI):

“Existing lightweight Bitcoin software often uses SPV or Simplified Payment Verification. While SPV allows some level of verification, it is susceptible to attacks that fully validating nodes aren’t.”

“Utreexo” according to him “…fully validates, while getting some of the low-footprint benefits the SPV nodes enjoy. Utreexo replaces the UTXO set of Bitcoin, which is the database that keeps track of who owns which coins, with a novel cryptographic accumulator.”

What it can achieve 

Essentially, Utreexo compacts the whole Bitcoin blockchain data into a few kilobytes,  thus a full node in itself. This opens up a new possibility for the bitcoin network, not necessarily for miners or full nodes but for the security of wallets and services operating on or relying on the data from the blockchain:

“The current Utreexo code is able to connect to a server, download the blockchain, and verify all the transactions and signatures, and do so using hardly any disk space.”

Ayobami Abiola,  a cryptocurrency enthusiast and writer at The Currency Analytics opined:

“#Utreexo is bringing back the lights in the Bitcoin network when almost everyone had given up. We all believe there is nothing else one can do about #bitcoin huge blockchain size,  but having the whole blockchain data in a second  on a device is a great feat.”

The code is still in its testing phase and not yet introduced to the network. The developers of Utreexo have shown their desire to work with minds from all over the world to share ideas as the project is open-sourced and on Github.

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