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I propose a realistic solution to using Ethereum as a public ledger

Problems are gas cost and capacity

We will face two problems with using Ethereum as a public ledger. The first one is the gas cost. Storing data to storage is the most expensive operation. (see SSTORE gas cost) The other one is capacity. …


Near future, our team will use IPFS for production service so I investigated lots about the configuration of it. I’m going to share my learned knowledge.

1. Preparation

At first, export “IPFS_PATH”.

export IPFS_PATH=/data/ipfsrep

The IPFS repository is created to this path. The default path is your $HOME. …


Setting ssl to Application Gateway using Ubuntu VM. I was so tired to achieve this, so I left my knowledge here.

In Azure, there are 2 types of load balancer. One is Load Balancer and the other is Application Gateway. If you want to support https, only Application Gateway is…


Blockchain is a good target to establish sharing economy, because the lessor and lessee can connected each other without any intermediates, like Uber or Aribnb. So, the lessor no longer be bothered by high margin cost.

Origin Protocol is the pioneer of sharing economy on top of the Ethereum. …


Gas efficiency tend to be low prioritized in most of the case. Since many projects pay attentions on security or cording readability. This time, I focus on gas cost saving.

Then, I introduce 13 tips to reduce gas cost.

Pre conditions

  • The gas cost is calculated by Remix as compiler version is…


Quantstamp is a smart contract security audit system by scalable and cost-effective way. I express Quantstamp contracts as Javascript for better understanding. Please refer to white paper or official blog for more information.

GitHub: quantstamp-contracts-js

Brief overview of Quantstamp

The smart contract security is essential to prevent security incident like the DAO. Unfortunately, Current…


I express Plasma MVP as Javascript for a better understanding of my study. MVP is minimal viable plasma which is originally proposed by Vbuterin aiming to provide the basic security properties of Plasma in a very simplified way.

Based on this proposal, OmiseGo implemented MVP for research aiming to use…


uPort is famous Ethereum project. In my opinion, uPort is the most successful self sovereign identity platform around blockchain. So I think understanding its strategy is helpful for our career.

I express uPort contracts and IPFS or other objects as javascript. Then I simulate how work uPort is. Honestly, I…


uPort is famous Ethereum project. In my opinion, uPort is the most successful self sovereign identity platform around blockchain. So I think understanding its strategy is helpful for our career.

I express uPort contracts and IPFS or other objects as javascript. Then I simulate how work uPort is. Honestly, I…


When I studied about uPort which is famous for self sovereign identity platform on Ethereum, I struggled to create JWT(uPort achieve off-chain identification by JWT). So, I note my experience for future learner.

Working sample code on Gist: jwt-secp256k1-secp256r1.js

Error happen

We can use ECDSA public/private key pair to sign JWT as…

tak

Japanese software engineer. Like blockchain, sauna and manga. re795h@gmail.com

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