Censorship of Harmful Data in Blockchains

Reading Time: 17 minutes

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?

A Short Guide Through the Universe of Blockchain Based Micropayment Systems

Reading Time: 7 minutes

Micropayment take place in pay-as-you-go software service models, micro donations, and the Internet of Things (IoT). In these contexts payments for values which are usually under the smallest unit of fiat money (e.g. $0.001) are needed. Prepaid cards can solve this problem. Another approach uses cryptocurrencies in the blockchain, having the advantage of allowing exact […]

Some Insights into Cardano ´s Blockchain

Reading Time: 5 minutes

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.

Comparison of PoS projects: Unbiased Leader Election

Reading Time: 7 minutes

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