In the blockchain-the terminology and the concept of Stale blocks. In the Russian version of such blocks is called uncoupled, abandoned or stale. They are not included in the main chain, and are often created by miners by accident, when the generation of the two participants is made at the same time. In this case, the single block becomes part of a chain, and the second is "orphan". Another option, when the creation of such a digital object is performed by hackers. This is done in order to make an attack on the network.
Another option is to Orphan (orphan's) block. This is not a bug and not the result of actions of malefactors. So in the official terminology of the developers of Bitcoin Core is the element whose parent block is not processed and Noda is still unknown. But ordinary users often confuse or combine these fundamentally different concepts. Moreover, the confusion and the staff make up some Internet media, like Blockchain.info.
But "orphans" parent relationships are formed over time and they become a part of the circuit, while the cast/zadworny unit has no such ability. Because it is a double, a sort of a clone of an already existing and proven equivalent.
The problems associated with the creation of Stale blocks
People involved in mining, are rewarded for the work of the crypto-units in your network. If his action coincided with the same from another miner, the network randomly selects one of them. The winner gets a "prize", and the loser loses time and money spent on electricity consumed by the equipment. Plus, the wear on equipment and other details.
Another unpleasant nuance – like draw blocks of copy tend to accumulate with lyingEnem. They create a lot of difficulties, and the main it does not error, and the possibility for a hacker to deploy his unit. The so-called "attack 51%" give the opportunity to control a significant percentage of the hashing power.
What happens in the end? Offender duplicates the network, creating a controlled counterpart, copy. As soon as she acquires a "sweep" algorithm of Bitcoin begins to consider her main priority. In such circumstances, the possible "roll" transactions. That is, the cancellation of already confirmed transfers and re-consumption.
This opportunity is used not only crypto-hackers but also some ordinary participants of the network. On the basis of this schema was created a concept called "Selfish mining" set forth five years ago by scientists at Cornell University I. Eyal and E. sirer Gyun the.
In total, we have several problems:
- The blockchain more vulnerable than we were trying to prove with 2009;
- Any group of users can theoretically violate the principle of decentralization and capture of the resources;
- Until there is an adequate solution to the problem;
- Pools attack each other;
- Miners don't want full decentralization, understanding that they will lose the opportunity to manipulate the system.
Experts showed an example of how users can create chains of abandoned blocks, manipulating bloccano, which has long been considered protected from hacking. That the scheme worked better cheaters "show" the chain immediately, but when its size is comparable with the present. The danger can come from any large pool that has large computing power.