The myth of the privacy of bitcoin long ago debunked. Guard of anonymity, there are such crypto-currencies like Monero, Dash, Verge and zcash for (it is Edward Snowden was identified as the most interesting cryptocurrency because of the «truly unique» characteristics of privacy). «King» does not suffer from such roles — his loyal subjects appreciate his other qualities. In addition, many mixers, applications for anonymization that are «mixed» coins from various transactions and send the right amount of coins (already not tied to your wallet) to the address specified, achieve a high level of anonymity, even when using bitcoin.
However, Ethereum are all clearly takes a different stance on the issue of privacy, and this is partly because the nature of its application. Today on the Ethereum blockchain works 1763 decentralized applications, many of which are interested in the privacy of transactional data. In February 2017 was formed by a consortium of Ethereum Enterprise Alliance (EEA), one of whose main tasks is to adapt the public blockchain Ethereum for corporate use. In early may, the EEA presented the first results of the work — a standardized architecture of Ethereum applications. Then the Executive Director of the consortium Ron Resnick said that «the biggest internal dispute» in the EEA was around the aspect of privacy, namely around how much information must be transmitted in each case. One of the members of the consortium, the financial holding company JPMorgan Chase, introduced to your corporate blockchain Protocol proof zero-knowledge — Zero Knowledge Proof — which is the basis of the zcash for cryptocurrency. EEA has not yet provided standardized mechanisms for privacy protection: «There are various ways to implement this idea: this can occur in the core network or offscan or there,» said Resnick, also noting that JPMorgan is actively involved in the development.
Meanwhile, another 5 projects are ready to offer their services Ethereum to increase privacy.
Secret store Parity
The second client Ethereum — Parity — in may introduced a private transaction functionality that allow you to create encrypted smart contracts. These transactions have the characteristics of exclusivity, that is, their status is only a limited number of approved participants, among which are distributed the keys. «Private transactions are, in essence, smart contracts, and the code, and the state of which is encrypted. First, the transaction is offscan a certain number of validators (established by contract), and they all have to come to an agreement on a new state, and then you take a new encrypted state with the signatures of all the validators and update the status of onchan. The separation of keys using a cryptographic scheme that allows a number of parties… safely to obtain parts of the key from the place that we call the secret store,» explained the developer Parity on Reddit.
Conclusion in onchan allows you to work with a contract in a real core network, while not revealing its data and status to all users of the blockchain. Jutta Steiner, CEO of Parity Technologies, notes that the new software encrypts the vault, and the code of the smart contract, that is provided that you trust the chosen key holders, «it provides privacy to any transaction which the contract models and performs».
In may, Steiner reported that ACCORDING to a secret storage is already being tested in partnership with an international pharmaceutical company that used it in the supply chain. July 25 Parity published a guide describing how to configure a secret storage with three nodes.
«I believe that the blockchain is strong by itself, but it becomes even more interesting when you combine it with other encryption technologies to make this finally the perfect anonymous computer, global computer on which you can rely and that [it] fast,» said Steiner in conversation with Coindesk.
Secret contracts Enigma
Enigma — the privacy Protocol for the creation of decentralized applications with the functionality of a secret contract that allows you to share sensitive information with third parties, without putting the data at risk and protecting them from government surveillance or disclosure due to hacker attacks or leaks. Co-founder of Enigma Kahn Kishon believes that Ethereum startups developing solutions in the field of voting, geolocation, social media and identity, suffer from the radical transparency of the blockchain, while the technology Enigma «allows you to create a truly decentralized secure applications, solving the problem of privacy».
According to members of the project, «a critical component to the success of the «smart economy» and the blockchain» is the ability of decentralized applications to analyze the data, keeping them completely private. The solution offered by the Enigma that is the decision of the second level, ofcan network with the use of «secret contracts» that hide data from the GBR network. In the mechanism of secret contracts and implemented the concept of «safe computing» — a set of technologies that allow computing with encrypted data.
«It can be thought of as a black box. You send any data they come in a black box, and back out only the result. Real data is never disclosed — either to the outside or the computers that carry out calculations inside» — says the guy Susskind, a member of the Media lab at MIT and CEO of Enigma.
Enigma encrypts the data, splitting them into several components and randomly distributing them in a hundred node network. Then each node performs calculations on the basis of the received data block, and ultimately only the data owner can combine the calculation results and decrypt them using the decryption key.
Oz Nathan, a member of the Enigma team, believes that guaranteed privacy will encourage app users to disclose more personal information: «Nobody wants to give their data to some company, not knowing what they will do with it,» says Nathan.
Kimono is a privacy project that aims to combine encryption with game theory. It was created in may, 36-hour Ethereum hackathon, held in Argentina.
Kimono uses a scheme of secret sharing Shamir cryptographic algorithm «restoring the mysteries», which allows to share information among the participants so that decoding is possible when combining data from all participants, and combines it with the incentive system, which is responsible for ensuring that participants disclose in a set time. If users try to cheat the system, falsified data, or revealing them too early, they are penalized.
«We believe the concept of temporarily blocking an important primitive (a basic element used to build more complex solutions. — DeCenter), and we would like to improve it and bring it to a level where it will be really decentralized and bestrasova,» said Feridun MERT Celebi, one of the founders of the Kimono. In his opinion, the scheme of incentives can be extended so that time was not the only variable that «releases» the secret: it may also be disclosed after a certain event or after a number of conditions, is made on the blockchain.
Currently running in a test Ethereum — Rinkeby.
Proposal for the improvement of Ethereum EIP 1024 owned by the developer to Tope Alabi and represents another method of data encryption. «EIP 1024 allows you to generate key pair encrypt using your private key Ethereum. Then this new encryption key pair can be used for secure data transfer to any Ethereum address,» said Alabi in conversation with CoinDesk.
Thus, in the case of the adoption of this proposal, it will spread its influence to the whole of the Ethereum network. «This means that application developers don’t have to worry about how to develop mechanisms for the different implementations of encryption — they can just do their application,» says Alabi.
In his opinion, the solution to the problem of privacy will provide an influx of «next billion users on the blockchain»: «In the world of the blockchain where your public and private keys are essentially your digital identity, you need a way to transmit sensitive information so that it could not be censored by any centralized authority», — stressed Alabi.
The latest proposal to improve privacy Ethereum was presented during the Symposium on technologies to improve privacy (PETS), held last week in Barcelona.
It is assumed that Mobius will improve anonymity without the traditional compromises in the form of increasing the cost of transactions, or requirements to increase the amount of memory. Transactions that use the Mobius, are only slightly more expensive than the standard Ethereum transactions (according to the simulation, about $0.06), and their execution takes milliseconds.
Mobius will be able to hide the address of the sender and receiver to implement it cryptographically bestrasova way. Technically, this functionality is implemented in a cryptographic mechanism, ring signatures: it allows you to hide billing information, payment information mixing all the participants of the contract and the Mobius is in fact acting on the principle of the mixer. This new project promises not have the drawbacks of decentralized maksimovym services that require you to spend a large part of offscan or processes to perform many actions on the blockchain, which slows transaction processing and increases the fee.
Also Mobius implemented Stealth-keys — the kind of «darkened», but confirmed addresses that allow contracts to Mobius safely communicate (to send each other challenges and to share information).
Solutions implemented in Mobius, have compared with the technology of privacy Monero, which also uses the mechanism of ring signatures and Stealth system disposable addresses.
While the technology is not available to users of Ethereum, but the implementation Mobius open source was published by the British blockchain startup Clearmatics and, according to Rebecca Mercer, co-author of white paper Mobius, its implementation in Ethereum is not technically difficult. «Clearmatics is the full code, so you can literally just paste it into the Ethereum blockchain. Also they have a manual, so it is fairly well developed,» said Mercer in a conversation with Coindesk.
However, Mercer said that at the moment she is not aware of any attempts to introduce Mobius in the public blockchain Ethereum. And, in her view, this is surprising, since the demand for bitcoin-mixers are quite high.
Mercer suggested that the reason for the low interest Maximova service for Ethereum that making payments is not the main scope of Ethereum: «I think it has to do with how Ethereum is used today. It’s not what people expect — people don’t plan to use Ethereum for private transactions. It’s just not his trade offer — it is designed for decentralized applications, companies, traders and cryptococal» she said Coindesk.
However, Mercer also recognizes that the Mobius at the moment is not so convenient from the point of view of the user experience: «I Think mass adoption will require a user interface that is easy to pick up your anonymity, but the backend will check to see if you made a mistake, and then you can just carry out a transaction in one click,» says the researcher.
And though Mercer has doubts about the popularity of the anonymizer for Ethereum, the «more anonymous Ethereum» is a very influential supporters: «I am inclined to [need] privacy is much stronger than a couple of years ago,» wrote Vitaly Buterin in may on Reddit, and therefore there are all bases to believe that the efforts of the privately-oriented projects (at least some of them) will find its wide user.