# Enforcing Fairness in Blockchain Transaction Ordering | SpringerLink

ago
In simplistic terms: One side wants to follow the original Bitcoin idea of peer to peer cash and a plan to have bigger blocks; the other side wants to keep blocks small while transforming bitcoin into a settlement network.

These SVP’s are nodes that can also be termed as lightweight clients. This includes one notable benefit, i.e., Simple Payment Verification(SPV). They simply download the longest chain block headers and hence do not have to download the whole blockchain. To do all of these, they need to verify if it has the stored block headers for the longest chain. This is how Merkle tree implementation is done in bitcoin. The use of Merkle Trees, this way, can lead to multiple benefits.

To make Merkle trees work, hashing is used. The left hash value is known as Merkle Root or the Root Hash. The tree is created from the bottom up using the individual transactions hashes. The individual transaction hashes are also known as Transaction IDs. It simply does the hashing pairs of nodes repeatedly until only one hash value is left.

Most virtual currencies have used this process to coordinate everyone on the blockchain. In Bitcoin, the process of mining, or creating new Bitcoin, also has a second purpose of making sure everyone is making the same updates to their copy of the blockchain.

He also cares about LGBT+ issues and is a shabu shabu fanatic. Previously, he wrote for Caixin Global and TechNode, covering topics ranging from fintech to fan economy. Timmy Shen is a Taipei-based journalist at Forkast. Timmy holds an MS degree from Columbia Journalism School.

In the original documents describing Bitcoin, the virtual currency’s new database was not referred to as a blockchain. That makes it hard to go back and rewrite or monkey with the older records. But it got that name over time because all of the transactions coming onto the network were grouped into blocks of data and then chained together using sophisticated math. Academics have pointed out that this design existed before Bitcoin, but Bitcoin brought it to prominence.

The reason a distinction should be made between the cases follows the different probabilities for the scenarios to occur with a honest primary given the existence of the transactions by the committee members. While in Case I, this happens with probability of $$(1-\alpha )^2$$ , in Case II the corresponding probability is larger, namely it is $$1-\alpha$$ . This means that when Case II is detected the primary has higher chances to be honest than in Case I.

The pseudocode of the Helix block validation process is presented in Algorithms 1-2. Algorithm 1 refers to the process conducted by a committee while the validation described in Algorithm 2 refers to each node in the committee.

Most of the early efforts to imitate the Bitcoin blockchain were done by programmers looking to create virtual currencies with slightly different characteristics from Bitcoin, and that needed their own databases to store all the transactions. Over time, some of these new virtual currencies added on significant new features that updated the blockchain concept so that it could handle more kinds of information.

In this section, we explain that such a voting criterion does not utilize all information available by the committee members. On the other hand, a proposal of a dishonest primary would be selective and its number of such included transactions is expected to be lower than that implied by such a distribution. The process requires communication among the committee members earlier to the joint indication regarding the honesty of the block proposal. We proceed to describe an alternative and more accurate validation process than that proposed for cryptocurrency Helix. We follow the assumption of Helix, namely that an issued transaction has the fixed probability $$\alpha$$ to appear in a pool of pending transactions by each node, such that for a given transaction this probability is independent among the various nodes. Accordingly, a block proposal of a honest primary should include, with probability $$\alpha$$ , a transaction issued by other nodes satisfying a bound on its hash value.

A precise determination of these numbers should ignore multiplicities of the same transaction among nodes and thus requires communication among them. Unlike the scheme of Helix, in the proposed scheme there is no notion of a block approval by a single committee member and thus computing the minimal required number of such nodes is not necessary. Thus, each transaction that has to be included should contribute equally to that decision, either positively if it is indeed included, or negatively if it is not included. Accordingly, the joint decision for the nodes is made based on these numbers. More specifically, the approval decision should determine whether the selection is fair. This can be computed by the number of expected transactions to be included and the number of those among them that are indeed included.

Bitcoin mining difficulty is a measure of how hard a miner would have to work to verify transactions on a block in the blockchain, or "dig out" Bitcoins. The mining difficulty reading is now at 27.69 trillion at a block height of 745,920, the lowest level since March. Such mining difficulty adjustments are highly correlated to changes in the mining hashrate — the level of computing power used during mining. Friday HKT, up 0.7% in the past 24 hours, according to data from CoinMarketCap. The difficulty level, which undergoes adjustments about every two weeks, reached a record high of 31.25 trillion on May 11. Bitcoin’s hashrate dropped to 193.2 exahashes per second on Thursday on a seven-day average from a record high of 231.4 exahashes on June 12, Binance Blockchain.com data showed. Bitcoin’s price stood at US\$23,039 at 11 a.m.