Cryptocurrencies are not only “electronic money”, but also other useful features.

“Rabbits are not only valuable fur ...”

The last year the hype around the cryptocurrency does not subside: the exchanges are growing, as if by leaps and bounds, major services for working with e-currency are opening (and closing ) - both stores and payment systems, there are discussions in the US Senate. And all this against the background of jumping courses and general hysteria about prices and the possibility of rapid enrichment.

At the moment, we see that cryptocurrency is still a “thing in itself”: computational capabilities are used exclusively to generate hashes by various algorithms. There are many different variations on the theme “Algorithm for CPU only”, “Algorithm mostly for ASICs”, various algorithms for auto-tuning network complexity, etc. But in fact this is a variation on the same topic: computing power go exclusively to the generation of new coins.

I must say that there were attempts to change the current situation. Primecoins work with prime numbers, the CureCoin project is also testing, with the aim of at least generating parallel coins and working with protein folding , as a maximum - adding @ home projects to the work algorithm. Undoubtedly, this is a big step forward for cryptocurrency as a means of scientific research. In this case, people who want to get some reward for using their power can also contribute to science.
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But such calculations are only one of the possibilities of a decentralized cryptocurrency network. Two days ago, another great idea was presented on bitcointalk.org, especially relevant in the light of the latest news about censorship on the Internet, closing torrent trackers, etc. One of the bitcointalk participants decided: why not store some arbitrary information in the blockchain file that can be attached to a network transaction, and then get it from this file at any time? Judge for yourself: a simple bash script will allow you to save all magnet links of a large torrent tracker in a file that will be copied many times over to a huge number of network nodes. Moreover, any person can save such information, and it is impossible to remove it by whim. On the basis of such a repository, it is possible to do very interesting things, and such content can no longer be deleted - as long as at least one node of the network works, the content will be available. True, the size of one “attachment” cannot exceed 128 KB, and the size of one block is 1MB, but for archived text data this is quite enough.

In fairness it should be noted that similar functionality has already been introduced in Namecoin. However, Namecoin contained certain rules for stored information, i.e. the stored data could be “incorrect”, and in the case of Datacoin all information is stored as BLOBs, which removes any format restrictions.

It turns out that this cryptocurrency scheme is unique: the currency itself is at the same time a product (place in a decentralized repository) and a means of calculation (you can exchange it for another cryptocurrency or “ordinary money” / fiat).

It is worth noting the disadvantages of this approach. First, an increase in blockchain file size can go up to 500 GB per year. However, with the current hard drives 500 GB - not so much (of course, when it comes to SSD), and the idea of ​​the currency implies a reward for providing for the general use of its free space. Secondly, the forum noted that no one bothers attackers to add prohibited content to the repository. It's hard enough to object, but my opinion is based on the fact that you cannot equate a certain file (chain of blocks), from which with the help of a number of special programs you can extract something forbidden, to the usual archive of "forbidden images". With the same success, you can write a program that extracts a certain sequence of bytes from the standard Windows files and writes these bytes to the 1.jpg file, which suddenly turns out to be part of such a comic book. Well, the third drawback, in my opinion, is the fact that you can simply “spam” the storage with unnecessary information. However, as far as I know, the existing functionality is added to avoid such a problem.

I would like to hear your views on the future of this concept. At the moment, Datacoin is the only cryptocurrency with such an “applied” purpose, and this again shows that such projects can serve the benefit of not only their own wallets, but also for the benefit of other people.

Disclaimer: I have nothing to do with this development, all information is gathered exclusively from bitcointalk.org.

PS Someone wrote on the forum: “Imagine an archive of Snowden, which is backed up on the computers of millions of users!” Especially considering the fact that the cryptocurrency mechanism allows them to work through Tor \ I2P - really, imagine this scenario!

UPD: some interesting ideas from the forum about the use of such a repository. Clarify: to save N kilobytes of data in the blockchain, you need to pay a small network tax, which is very reasonable.
1. Storage of encrypted information (including personal) in the form of “public key - encrypted information”, there is already a simple script for encoding / decoding files in this way. Such information can be not only a “note on memory”, but also some data with a critical time of the first appearance on the network. For example, if you need to prove the authorship of a scientific discovery, you can specify: here is the base of the hashes, here is my information about the discovery, here is the time it was saved. It is impossible to edit and tamper with the data, therefore this can serve as evidence.
By the way, this way you can store, for example, the same encrypted bitcoin wallet, and it cannot be accidentally deleted from the googledrive account. A sort of analogue of the bank.
2. In the future, it is possible to use such a database as an auxiliary storage for “anonymous twitter”: you do not need to go through the registration procedure in such a “twitter”, you do not need to “shine” your personal data, etc., you just need to send a transaction with data in a certain format , and they appear on the site. Naturally, in this case it will be possible to limit the size of the data for such messages, as was done on the original twitter.
3. to be continued ...