Connect with us

Blockchain

Introducing MultiChain Streams

Avatar

Published

on

For shared immutable key-value and time series databases

Today we’re proud to release the latest version of MultiChain, which implements a crucial new set of functionality called “streams”. Streams provide a natural abstraction for blockchain use cases which focus on general data retrieval, timestamping and archiving, rather than the transfer of assets between participants. Streams can be used to implement three different types of databases on a chain:

  1. A key-value database or document store, in the style of NoSQL.
  2. A time series database, which focuses on the ordering of entries.
  3. An identity-driven database where entries are classified according to their author.

These can be considered as the ‘what’, ‘when’ and ‘who’ of a shared database.

Streams basics

Any number of streams can be created in a MultiChain blockchain, and each stream acts as an independent append-only collection of items. Each item in a stream has the following characteristics:

  • One or more publishers who have digitally signed that item.
  • An optional key for convenient later retrieval.
  • Some data, which can range from a small piece of text to many megabytes of raw binary.
  • A timestamp, which is taken from the header of the block in which the item is confirmed.

Behind the scenes, each item in a stream is represented by a blockchain transaction, but developers can read and write streams with no awareness of this underlying mechanism. (More advanced users can use raw transactions to write to multiple streams, issue or transfer assets and/or assign permissions in a single atomic transaction.)

Streams integrate with MultiChain’s permissions system in a number of ways. First, streams can only be created by those who have permission to do so, in the same way that assets can only be issued by certain addresses. When a stream is created, it is open or closed. Open streams are writeable by anybody who has permission to send a blockchain transaction, while closed streams are restricted to a changeable list of permitted addresses. In the latter case, each stream has one or more administrators who can change those write permissions over time.

Each blockchain has an optional ‘root’ stream, which is defined in its parameters and exists from the moment the chain is created. This enables a blockchain to be used immediately for storing and retrieving data, without waiting for a stream to be explicitly created.

As I’ve discussed previously, confidentiality is the biggest challenge in a large number of blockchain use cases. This is because each node in a blockchain sees a full copy of the entire chain’s contents. Streams provide a natural way to support encrypted data on a blockchain, as follows:

  1. One stream is used by participants to distribute their public keys for any public-key cryptography scheme.
  2. A second stream is used to publish data, where each piece of data is encrypted using symmetric cryptography with a unique key.
  3. A third stream provides data access. For each participant who should see a piece of data, a stream entry is created which contains that data’s secret key, encrypted using that participant’s public key.

This provides an efficient way to archive data on a blockchain, while making it visible only to certain participants.

Retrieving from streams

The core value of streams is in indexing and retrieval. Each node can choose which streams to subscribe to, with the blockchain guaranteeing that all nodes which subscribe to a particular stream will see the same items within. (A node can also be configured to automatically subscribe to every new stream created.)

If a node is subscribed to a stream, information can be retrieved from that stream in a number of ways:

  • Retrieving items from the stream in order.
  • Retrieving items with a particular key.
  • Retrieving items signed by a particular publisher.
  • Listing the keys used in a stream, with item counts for each key.
  • Listing the publishers in a stream, with item counts.

As mentioned at the start, these methods of retrieval allow streams to be used for key-value databases, time series databases and identity-driven databases. All retrieval APIs offer start and count parameters, allowing subsections of long lists to be efficiently retrieved (like a LIMIT clause in SQL). Negative values for start allow the most recent items to be retrieved.

Streams can contain multiple items with the same key, and this naturally solves the tension between blockchain immutability and the need to update a database. Each effective database ‘entry’ should be assigned a unique key in your application, with each update to that entry represented by a new stream item with its key. MultiChain’s stream retrieval APIs can then be used to: (a) retrieve the first or last version of a given entry, (b) retrieve a full version history for an entry, (c) retrieve information about multiple entries, including the first and last versions of each.

Note that because of a blockchain’s peer-to-peer architecture, items in a stream may arrive at different nodes in different orders, and MultiChain allows items to be retrieved before they are ‘confirmed’ in a block. As a result, all retrieval APIs offer a choice between global (the default) or local ordering. Global ordering guarantees that, once the chain has reached consensus, all nodes receive the same responses from the same API calls. Local ordering guarantees that, for any particular node, the ordering of a stream’s items will never change between API calls. Each application can make the appropriate choice for its needs.

Streams and the MultiChain roadmap

With the release of streams, we’ve completed the last major piece of work for MultiChain 1.0, and are now firmly on the path to beta. We expect to spend the next few months expanding our internal test suite (already quite large!), finishing the Windows and Mac ports, adding some more useful APIs, updating the Explorer for streams, tweaking aspects of the consensus mechanism, releasing our web demo, and generally tidying up code and help messages. Most importantly, we’ll continue to fix any bugs as soon as they’re discovered, so that our mistakes don’t interrupt your work.

In the longer term, where do streams fit into the MultiChain roadmap? Taking a step back, MultiChain now offers three areas of high-level functionality:

  • Permissions to control who can connect, transact, create assets/streams, mine/validate and administrate.
  • Assets including issuance, reissuance, transfer, atomic exchange, escrow and destruction.
  • Streams with APIs for creating streams, writing, subscribing, indexing and retrieving.

After the release of MultiChain 1.0 (and a premium version), what’s next in this list? If you look at the API command which is used to create streams, you’ll notice an apparently superfluous parameter, with a fixed value of stream. This parameter will allow MultiChain to support other types of high-level entity in future.

Possible future values for the parameter include evm (for an Ethereum-compatible virtual machine), sql (for an SQL-style database) or even wiki (for collaboratively edited text). Any shared entity whose state is determined by an ordered series of changes is a potential candidate. Each such entity will need: (a) APIs which provide the right abstraction for updating its state, (b) appropriate mechanisms for subscribed nodes to track that state, and (c) APIs for efficiently retrieving part or all of the state. We’re waiting to learn which other high-level entities would be most useful, to be implemented by us or by third parties via a plug-in architecture.

What about smart contracts?

In a general sense, MultiChain takes the approach in which data is embedded immutably in a blockchain, but the code for interpreting that data is in the node or application layer. This is deliberately different from the “smart contracts” paradigm, as exemplified by Ethereum, in which code is embedded in the blockchain and runs in a virtual machine. In theory, because smart contracts are Turing complete, they can reproduce the behavior of MultiChain or any other blockchain platform. In practice, however, Ethereum-style smart contracts have many painful shortcomings:

  • Every node has to perform every computation, whether it’s of interest or not. By contrast, in MultiChain each node decides which streams to subscribe to, and can ignore the data contained by others.
  • The virtual machine used for smart contracts has drastically worse performance than code which has been natively compiled for a given computer architecture.
  • Smart contract code is immutably embedded in a chain, preventing features from being added and bugs from being fixed. This was demonstrated forcefully in the demise of The DAO.
  • Transactions sent to a smart contract cannot update a blockchain’s state until their final ordering is known, because of the nature of general purpose computation. This leads to delays (until a transaction is confirmed in a block) as well as possible reversals (in the event of a fork in the chain). By contrast, MultiChain can treat each type of unconfirmed transaction in the appropriate way: (a) incoming assets immediately update a node’s unconfirmed balance, (b) incoming stream items are instantly available, with their global ordering subsequently finalized, (c) permissions changes are applied immediately and then replayed in incoming blocks.

Nonetheless, as I’ve said before, we’re certainly not ruling out smart contracts as a useful paradigm for blockchain applications, if and when we see strong use cases. However, in MultiChain smart contracts would be implemented in a stream-like layer on top of the blockchain, rather than the lowest transaction level. This will preserve MultiChain’s superior performance for simpler blockchain entities like assets and streams, while offering slower on-chain computation where it’s really needed. But there are fewer such cases than you might think.

 

Please post any comments on LinkedIn.

 

Technical addendum

All commands related to streams are documented in full in the MultiChain API page, but here is a brief summary:

  • Create a stream using create stream or createfrom ... stream
  • Add an item to a stream with publish or publishfrom
  • Retrieve a list of streams using liststreams
  • Start or stop tracking a stream with subscribe and unsubscribe
  • Retrieve stream items using liststreamitems, liststreamkeyitems and liststreampublisheritems
  • List stream keys and publishers with liststreamkeys and liststreampublishers
  • For large stream items, retrieve the full data using gettxoutdata (see maxshowndata below)
  • Control per-stream permissions with calls like grant [address] stream1.write
  • View a stream’s permissions using listpermissions stream1.*

Some other developer notes relating to streams:

  • The create permission allows an address to create streams.
  • Relevant per-stream permissions are write, admin and activate
  • New blockchain parameters: root-stream-name (leave empty for none), root-stream-open, anyone-can-create, admin-consensus-create, max-std-op-returns-count
  • New runtime parameters: autosubscribe to automatically subscribe to new streams created and maxshowndata to limit the amount of data in API responses (see gettxoutdata above).
  • The maximum size of a stream item’s data is fixed by the max-std-op-return-size blockchain parameter, as well as the smaller of the maximum-block-size and max-std-tx-size values minus a few hundred bytes.
  • Nodes using the old wallet format cannot subscribe to streams, and should be upgraded.

 

Source: https://www.multichain.com/blog/2016/09/introducing-multichain-streams/

Blockchain

$500K Bitcoin Donation Funneled to Groups Involved in US Capitol Riot: Analysis

Avatar

Published

on

Blockchain intelligence firm Chainalysis has tracked simultaneous Bitcoin (BTC) donations to wallets associated with right-wing extremist groups in the U.S., which might have helped fund the recent riot at the U.S. Capitol. The news marks yet another pivot towards pseudonymous money transfer means by alt-right groups in the U.S.

Alt-Right Agitators Received $500K in Bitcoin Prior to US Capitol Riot

Publishing its findings on Thursday (Jan. 14, 2021), Chainalysis revealed that several notable alt-right personalities who were present at the Jan. 6 riot in the U.S. Capitol received substantial Bitcoin donations.

According to Chainalysis, a single donor funneled 18.15 BTC to addresses belonging to entities with right-leaning affiliations on Dec. 8, 2020. At the time, this figure was worth over $500,000.

In its report, Chainalysis also revealed that popular far-right political commentator Nick Fuentes received 13.5 BTC. There are a few photographic pieces of evidence placing Fuentes at the riot with a megaphone in hand though Fuentes has denied entering the building itself.

Apart from him, alt-right podcaster Ethan Ralph and VDARE — an anti-immigration organization — also received BTC sums from the donor. While Chainalysis did not reveal the identity of the person responsible for funneling the Bitcoin, the crypto forensics outfit did mention that there strong evidence that the donor is a French computer programmer.

An examination into the donor’s wallet shows that the person is likely an early Bitcoin adopter. Further investigation into the donor shows a history of donations to extremist causes with an alleged suicide note referencing known alt-right talking points.

Based on these findings, U.S. law enforcement officials are reportedly investigating possible links between the donations and the assault on the Capitol. Prosecutors also say that they are approaching the investigations from a counterterrorism and counterintelligence standpoint.

Financial Censorship Triggering Crypto Adoption

Alt-right groups receiving donations in Bitcoin is only the latest example of political and social groups with dissident ideologies embracing cryptocurrencies. Indeed, Bitcoin’s early history is somewhat intertwined with WikiLeaks especially after the establishment was cut off from mainstream funding sources.

Even countries facing economic sanctions are also adopting cryptocurrencies. Venezuela is a popular example, with the Maduro administration even creating its own oil-backed Petro “coin.”

Nations like Iran are actively supporting Bitcoin mining with tax breaks for BTC miners. As previously reported by CryptoPotato, the output from three power plants has been offered to miners in the country.

SPECIAL OFFER (Sponsored)
Binance Futures 50 USDT FREE Voucher: Use this link to register & get 10% off fees and 50 USDT when trading 500 USDT (limited offer).

PrimeXBT Special Offer: Use this link to register & enter CRYPTOPOTATO35 code to get 35% free bonus on any deposit up to 1 BTC.

You Might Also Like:


Source: https://cryptopotato.com/500k-bitcoin-donation-funneled-to-groups-involved-in-us-capitol-riot-analysis/

Continue Reading

Blockchain

Bitcoin Faced First Major Correction In Current Bull Run: The Crypto Weekly Market Update

Avatar

Published

on

This week was very intensive in the cryptocurrency market. It’s perhaps safe to say that it was among the most tumultuous ones we’ve had in the last few months.

Everything started calmly, and during the weekend, the price hit an all-time high value of $42,000. The excitement was short-lived, as immediately after that, bitcoin went in the opposite direction and started to decline. It wasn’t until Monday, however, when things took a turn for the worst.

Bitcoin’s price lost around $12,000 in what seems to be the first major correction in the ongoing bull run. The decline of around 27% came in a few brutal four-hour red candles and led to the liquidations of $2.87 billion worth of both long and short positions, indicating once again how over-leveraged the market is.

From there, the price took uphill and even reached $40,000 again on Thursday. Bears, however, weren’t done as what followed was another handful of red candles that brought the price to its current trading level of about $35,000.

With this said, the entire cryptocurrency market took a hit as the capitalization has dropped below $1 trillion. Meanwhile, Bitcoin’s dominance is also suffering, as it’s down to 67.7% during this week from its high of around 70.3%. This shows that despite the blood on the streets, altcoins have managed to take the upper hand and claim a larger portion of the market.

Meanwhile, two other projects made headlines over the past few days, mainly thanks to their incredible price performance. Despite this brutal correction, Polkadot’s DOT token is up 40% over the last seven days, while LINK is up 22%. The latter even charted a new all-time high today.

In any case, the week was particularly exciting, and even though this time it was the bears who had the upper hand, it’s very interesting to see how the next few days will shape up. Is this the beginning of a larger correction, or is it just a step back in preparation for an even bigger rally? We have yet to see.

Market Data

Market Cap: $964B | 24H Vol: 144B | BTC Dominance: 67.7%

BTC: $35,442 (-14.6%) | ETH: $1,141 (-7.5%) | XRP: $0.276 (-12.9%)

Tether (USDT) January 15th Deadline on iFinex Case: Everything You Need to Know. Today is an important date for the entire cryptocurrency industry as it marks a serious deadline on the iFinex v. NYAG case. Here is everything you need to know about it and what to expect.

FinCEN Extends Comment Window on Proposed Crypto Regulations. After receiving thousands of responses and serious criticism from industry participants, the Financial Crimes Enforcement Network (FinCEN) has decided to extend the comment window on the proposed cryptocurrency regulations.

Following Coinbase And Bakkt: Winklevoss’ Gemini Reportedly Considers Going Public. Cameron and Tyler Winklevoss are reportedly exploring the option of taking their cryptocurrency exchange, Gemini, public. This means that they could follow in the footsteps of other cryptocurrency-related companies with similar intentions – namely, Coinbase and Bakkt.

Greenlight: Anchorage Secures Crypto Banking Charter from the OCC. The United States Office of the Comptroller of the Currency (OCC) has granted a cryptocurrency custodial service company a national trust charter. This puts the firm in the position to claim the mantle of a US-based national crypto bank.

4 Possible Reasons for Bitcoin’s $12K Correction After Reaching $42,000 All-Time High. Bitcoin went through its first major correction this week, sliding by more than 27% in just a few four-hour red candles. Here are some of the potential reasons for which this happened.

Crypto Market Cap Reclaims $1 Trillion as Bitcoin Sets Sights on $40K. The cryptocurrency market sees no boring days. Just a couple of days back, it was on its way back up, recovering from a major correction, and even claimed $1 trillion in market cap again. Unfortunately, today things took a turn for the worst again.

Charts

This week we have a chart analysis of Bitcoin, Ethereum, Ripple, Polkadot, and Cardano – click here for the full price analysis.

SPECIAL OFFER (Sponsored)
Binance Futures 50 USDT FREE Voucher: Use this link to register & get 10% off fees and 50 USDT when trading 500 USDT (limited offer).

PrimeXBT Special Offer: Use this link to register & enter CRYPTOPOTATO35 code to get 35% free bonus on any deposit up to 1 BTC.

Disclaimer: Information found on CryptoPotato is those of writers quoted. It does not represent the opinions of CryptoPotato on whether to buy, sell, or hold any investments. You are advised to conduct your own research before making any investment decisions. Use provided information at your own risk. See Disclaimer for more information.

Cryptocurrency charts by TradingView.


Source: https://cryptopotato.com/bitcoin-faced-first-major-correction-in-current-bull-run-the-crypto-weekly-market-update/

Continue Reading

Blockchain

Report: Mt Gox Creditors Could Claim 90% Of The Owned Bitcoins After A CoinLab Deal

Avatar

Published

on

Nearly $5 billion in bitcoin could make their way back to Mt. Gox users following a deal between creditors and CoinLab. Nevertheless, the agreement is still reportedly subject to creditor acceptance.

  • Bloomberg reporter Matt Leising offered a brief explanation of the story earlier today, noting that CoinLab has reached a deal with Mt. Gox creditors for 90% of the bitcoins they are owned.
  • Should the deal indeed proceed, the creditors would receive over 135,000 bitcoins out of 150,000. With today’s prices, this sizeable amount has a value of $4.8 billion. 
  • As those users have been waiting for over six years to receive their coins, whose value has appreciated significantly, the community speculated that they might dispose of the bitcoins, which could harm the market.
  • Founded in 2011, CoinLab partnered with Mt. Gox in late 2012 to handle transactions for the exchange in the North American region. However, the collaboration ended rather shortly as CoinLab took Mt. Gox to court, alleging that the trading platform had broken its contractual agreement. 
  • The Japan-based crypto exchange was the largest trading platform years ago, responsible for over 70% of the BTC transactions during its peak. However, it all crumbled after one of the largest hacks in the cryptocurrency field in which the attackers took 850,000 bitcoins – worth over $30 billion today.
SPECIAL OFFER (Sponsored)
Binance Futures 50 USDT FREE Voucher: Use this link to register & get 10% off fees and 50 USDT when trading 500 USDT (limited offer).

PrimeXBT Special Offer: Use this link to register & enter CRYPTOPOTATO35 code to get 35% free bonus on any deposit up to 1 BTC.

You Might Also Like:


Source: https://cryptopotato.com/report-mt-gox-creditors-could-claim-90-of-the-owned-bitcoins-after-a-coinlab-deal/

Continue Reading
Blockchain4 days ago

Blockchain Bites: Bitcoin Rebounds, Addresses Above 2017 Peak, Sci-Hub Decentralizes

Blockchain4 days ago

JP Morgan Warns a US Bitcoin ETF Could Bust BTC Prices in the Short Term

Blockchain4 days ago

Bitcoin News Roundup for Jan. 12, 2021

Blockchain4 days ago

ICM.com Bridges Gap Between Crypto and Oil Markets with BTCOIL

Blockchain4 days ago

Bitcoin faces uncertainty of “tapering”, hints Fed Chair

Blockchain4 days ago

Tron Is Out, Dai Is Back: CoinDesk 20 List Updates for 2021 Q1

Blockchain5 days ago

Bitcoin News Roundup for Jan. 11, 2021

Blockchain4 days ago

Bitcoin Will Be Analogous to Amazon, Mark Cuban Compares Crypto to the Dot-Com Bubble

Blockchain4 days ago

German authorities take down DarkMarket, allegedly the world’s largest Dark Web marketplace

Blockchain4 days ago

Cardano’s Mary hard fork to offer native multi-asset support in February

Blockchain5 days ago

Stacks 2.0 To Bring Dapps And DeFi To Bitcoin

Blockchain4 days ago

JP Morgan Warns a US Bitcoin ETF Could Bust BTC Prices in the Short Term

Blockchain4 days ago

Michael Saylor Announces ‘Bitcoin for Corporations’ Educational Event

Blockchain4 days ago

Fidelity doubles down on Hong Kong crypto operator

Blockchain4 days ago

Telegram Sees 25 Million New Users in 72 Hours

Blockchain4 days ago

Peter Schiff Tosses Claims of False Institutional Bitcoin (BTC) Purchases, T. Winklevoss Rebuts

Blockchain4 days ago

Ruffer Investment: Bitcoin Is ‘A Unique Beast as an Emerging Store of Value’

Blockchain4 days ago

What is USDC? Beginner’s Guide (2021)

Blockchain4 days ago

An Upcoming Public Sale on Polkastarter Follows e-Money’s Successful DEX Launch

Blockchain4 days ago

HSBC Blocks Transactions From Crypto Exchanges

Blockchain4 days ago

Here’s why Bitcoin miners are unlikely to sell-off their holdings

Blockchain4 days ago

EIP 1559 Almost Ready, Might Go Out by Summer Says Tim Beiko

Blockchain4 days ago

Seven times that US regulators stepped into crypto in 2020

Blockchain4 days ago

This Project May be Fiat’s Layer 2 Solution

Blockchain4 days ago

JP Morgan Warns a US Bitcoin ETF Could Bust BTC Prices in the Short Term

Blockchain4 days ago

First Mover: Market Signs Look Healthy as Bitcoin Sell-Off Subsides

Blockchain4 days ago

The Issuer of Tether (USDT) May Get Audited in 2021

Blockchain5 days ago

HSBC Blocks Transactions From Crypto Exchanges

Blockchain4 days ago

The Story of Satoshi’s First Ever Bitcoin Transaction

Blockchain4 days ago

Founder of a $147M Crypto Ponzi Scheme Sentenced to 10 Years in Prison

Blockchain4 days ago

Huobi Now Supports RUB Deposits and Withdrawals, Announces Crypto Purchase Campaign

Blockchain3 days ago

WAX Launches New DeFi Model to Share Revenue Earned From NFT Sales

Blockchain4 days ago

Crypto Fund Manager Grayscale Reopens Deposits for New Clients

Blockchain4 days ago

Flash loan attack explained | Part1 | DeFi: In & Out

Blockchain4 days ago

Fat-BTC Review 2021: What is the Fat-BTC exchange?

Blockchain4 days ago

Bitcoin Will Be Analogous to Amazon, Mark Cuban Compares Crypto to the Dot-Com Bubble

Blockchain5 days ago

Time to Take Money Off The Table: Guggenheim CIO Amid the Bitcoin Plunge

Blockchain4 days ago

Here’s Why Coinbase Keeps Going Down During Bitcoin Rallies

Blockchain3 days ago

The Bitcoin Dream Is Dead

Trending