Public blockchains allow insertion of arbitrary data. Even specific-purpose blockchains like Bitcoin already contain a lot of non-financial data. Although this data insertion can be beneficial in some use cases (e.g. proof of existence), it can also cause damage. If a blockchain contained videos with instructions on how to torture someone, there would immediately be broad consensus that this data must be deleted. But since blockchains are supposed to be immutable databases, the question is: what can be done if this happens?
Any information stored in a blockchain is supposed to be preserved forever, nobody will be able to change it or even less erase it. But is this really true? Is there any chance that governments or private groups with enough money to finance costly attacks might delete information from a blockchain?
This is a step by step guide that shows how to publish a text in the Roptsten testnet of Ethereum. In order to publish in the Mainnet you will need to select it in the first step of the following tutorial.
After testing the performance of Ethereum using PoA, we tested the usability of the CardContact SmartCard-HSM USB token on an ethereum Proof of Authority network. The HSM allows to store and use multiple encryption keys, both RSA and Elliptic Curves (including secp256k1), for applications like issuing certificates as a CA, and with any application that […]
Lately, there has been a lot of talk about permissioned blockchains, in which only certain entities have the authority to validate transactions and generate blocks. The use of these technologies is currently highly required by different companies, since it allows them to store data in a decentralized way and show complete transparency in all their […]
In this blog post, we present a high-level overview of the paper describing the Ouroboros Proof of Stake protocol implemented in Cardano´s blockchain. After the overview follow some comments about theoretical aspects of the protocol.
In general, Proof of Stake (PoS) consensus protocols elect the network nodes responsible to send the next block to the blockchain on the basis of the nodes’ amount of stake.
At CoinFabrik we are organizing internal presentations in response to interesting work we are doing. As we have grown, scheduling time to share our projects and ideas has become essential. Recent presentations have included: Decentralized Blockchain Bridges Last year Oscar Guindzberg, TrueBit, and CoinFabrik partnered to create a decentralized trustless bridge between Dogecoin and Ethereum […]
Prior to the Bitcoin blockchain of “Satoshi Nakamoto”, distributed ledger systems were lacking two important properties which are essential for a decentralized digital cash system. The first property which existing distributed ledger systems were missing, was the ability to scale to a network of millions of users. And secondly, systems at the time were not permissionless
Introduction Public blockchains are not suited to function as a data storage provider. Since they are append-only ledgers, storing many large files would result in a dramatic increase of the whole distributed ledger. That would force the network nodes to store huge databases leaving it in the hands of just a few providers. Likewise, the […]
We are compiling a list of recent technologies developments in the blockchain sector. Our focus is mostly on projects which promise scalability, but includes also proposals which aim to overcome some deficiencies in Bitcoin´s PoW based blockchain, e.g. which aim to improve fairness, usefulness, or privacy. You can find the current state of our work […]
Elliptic curve cryptography is becoming more and more popular. One of its main supporters is the cryptocurrency system Bitcoin which uses an elliptic curve scheme for their digital signatures. Smaller key size, a more efficient implementation than the RSA system, and a similar level of security make elliptic curve cryptography an interesting alternative to RSA. […]
A private ethereum blockchain with multiple geth instances can be run over a network or on the same computer. We will explain how to do both, and also how to solve some common issues. Configuring genesis.json We need to create a JSON file, which will represent the genesis block of our private blockchain. This file […]