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Introducing MultiChain Streams

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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

Bitcoin Sees Largest Exchange Inflows Since March 2020 Crash

Another bearish signal for Bitcoin as the cryptocurrency sees the largest exchange inflows from external wallets last seen in March 2020.

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Another bearish signal for Bitcoin has been looming around the corner with the digital asset seeing the largest inflows from external wallets to spot exchanges last seen in March 2020, signifying investors are ready to sell-off their holdings.

Bitcoin Sees the Highest Daily Spike in Exchange Inflows

Having already lost over 50% of its value from its all-time high in just two months, numerous technical indicators are signaling Bitcoin towards even more adverse price reactions.

Following reports of the digital asset crossing the much-dreaded “death cross”, new on-chain data reveals that investors are depositing massive portions of their holdings to exchanges in order to cash out their holdings.

READ  Gazprom’s Oil Unit Opens Crypto Mining Farm at One of Its Drilling Sites

For instance, data from CryptoQuant shows that on June 21 Bitcoin saw the highest daily spike in inflows from external wallets to spot exchanges, last seen during the COVID-19 induced March 2020 crash, that took the cryptocurrency to as low as $3,000.

Even though the leading cryptocurrency has recovered more than $10,000 from the previous weeks, the digital asset has indeed weakened due to China’s brutal crypto crackdown.

Stablecoin Inflows Drop Considerably

At the same time, data from CryptoQuant indicates that the stablecoin inflows to exchanges seem to have dropped as investors turn bearish on Bitcoin.

For instance, during the first five months of the year, the circulating supply of stablecoins was on a steady rise and accelerated somewhat as the market sold off in May. However, stablecoin issuance came to a standstill at the beginning of June as bearish trends took over the Bitcoin market.

READ  Altcoins Notch Multi-Year Highs as Bitcoin Price Move Towards $60K

Since then, stablecoin inflows to exchanges have fallen to their lowest level last seen in October 2020.

Usually, stablecoin inflows are viewed as bullish catalysts. However, CryptoQuant’s recent newsletter warns of similar spikes in stablecoin issuance in the past followed by a prolonged price declines:

 “After the bottom of the last bear market (2018-2019), we saw a steady rise in issuance events. At the top (June 28, 2019) of this bullish period, there was a large issuance event (the two big spikes in July-August 2019 are due to USDT ETH issuance). It looks like the same is happening right now.”

#Bitcoin #Bitcoin Inflows

Coinsmart. Beste Bitcoin-Börse in Europa
Source: https://www.cryptoknowmics.com/news/bitcoin-sees-largest-exchange-inflows-since-march-2020-crash

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Dogecoin Gets Hit the Hardest Among Top 10 Coins, Plunges Over 20%

Dogecoin has gotten hit the hardest among the top 10 coins and saw its second-worst day of the year on June 22 by plunging down over 36% to $0.17.

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Meme-based cryptocurrency Dogecoin gets hit the hardest among the top 10 coins and saw its second-worst day of the year on June 22 by plunging down over 36% to $0.17, the lowest level since Apr. 23.

Dogecoin Gets Hit the Hardest Among Top 10 Coins

On May 19, joke cryptocurrency Dogecoin shed over 55% within a single day, but it managed to climb back to almost half of the losses before the daily close.

The meme-based coin is currently trading 77% lower since May 8, from its current all-time high of $0.74 on May 8. The market cap, which was $34.97 billion on June 21, has now slid down to $27.22B in just the last 24 hours.

READ  Crypto Market Hits $200 Billion, Bitcoin Rallies To $7K: BCH, LTC, EOS, ADA Analysis

Dogecoin is currently the biggest loser among the top 10 cryptocurrencies, plunging over 20%, despite major altcoins like XRP, Binance Coin, and Polkadot experiencing double-digit losses.

The value of popular cryptocurrencies remained weak on June 22 after the crypto market witnessed a massive crash a day earlier, following China’s intensified crackdown on Bitcoin.

Over the bigger picture, Dogecoin looks weak that needs upside catalysts to rebound from current levels.

For instance, if Dogecoin declines below the support at $0.25, it will head towards the next support level at $0.2250. A successful test of the support at $0.2250 will push the cryptocurrency towards the next support at $0.2150.

Dogecoin-Branded NASCAR Crashes Like DOGE

Stefan Parsons’ car emblazoned with the Dogecoin logo crashed into the wall during Stage 2 at Nashville Superspeedway on June 19th. Fans of meme-based cryptocurrency fans pushed the hashtag #dogecar trend on Twitter.

READ  Vitalik Buterin Reveals Making $4.3M from $25,000 Investment in Dogecoin

The car was sponsored by Springates, a manufacturer of auto parts whose CEO is a DOGE enthusiast. Parson escaped unhurt but the value of the cryptocurrency did not.

DOGE has a long history on the NASCAR tracks. In April 2014, for instance, Dogecoin fans raised 68 million DOGE worth about $42,000 at the time, via a Reddit campaign to sponsor Josh Wise’s Ford Fusion car. Interestingly, Wise raced in the same team as Stefan Parsons’ father Phil.

#DOGE #Dogecoin

Coinsmart. Beste Bitcoin-Börse in Europa
Source: https://www.cryptoknowmics.com/news/dogecoin-gets-hit-the-hardest-among-top-10-coins-plunges-over-20

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VanEck to Launch a Mutual Fund that Invests in BTC Futures

Global investment manager VanEck has recently filed an introductory prospectus to launch a mutual fund that put its money into BTC Futures.

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Global investment manager VanEck has recently filed an introductory prospectus to launch a mutual fund that put its money into BTC Futures through its Cayman Islands-based subordinate. Rest, it has been revealed that the fund may also put some of its unsettled assets into the United States treasuries. 

VanEck to Initiate a Mutual Fund That Invests in BTC Futures

The Bitcoin Strategy Fund is not going to have any exposure to the spot price of the top crypto asset and it said:

“The Fund seeks to achieve its investment objective by investing, under normal circumstances, in bitcoin futures contracts (“Bitcoin Futures”), as well as pooled investment vehicles and exchange-traded products that provide exposure to bitcoin (together with Bitcoin Futures, “Bitcoin Investments”). The Fund does not invest in bitcoin or other digital assets directly.”

In addition to this, it has already been reported that the global investment manager VanEck has filed requisitions for both Bitcoin and Ethereum ETFs earlier this year.

However, the United States Securities and Exchange have not approved any of them as of yet. 

Moreover, the SEC has initiated the process of looking for additional comments to affirm whether or not it should checklist the Bitcoin ETF proposal of VanEck.

Mike Novogratz Comments on China Crypto Crackdown

The CEO of Galaxy Digital, Michael Novogratz has recently released a statement sharing his opinion on the effect of the ongoing China crackdown on crypto.

Novogratz took it to Twitter and said:

“China news isn’t good. Xi is an authoritarian leader who wants control over things. $BTC is the opposite of authoritarianism. Chinese citizens will always find a way to move assets outside the system but they are making it harder. Will take some time to play out. Keep the faith.”

Novogratz is sure that the Chinese Crypto owners will be able to shift their assets outside China, but it will take some time.

READ  Block.One Social Media Platform Voice Announces its Launch

#BTC futures #Mutual Fund #VanEck

Coinsmart. Beste Bitcoin-Börse in Europa
Source: https://www.cryptoknowmics.com/news/vaneck-to-launch-a-mutual-fund-that-invests-in-btc-futures

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Yearn Finance (YFI) and Synthetix (SNX) Technical Analysis: What to Expect?

Synthetix and Yearn Finance are sinking. If $7 falls, SNX/USDT may halve to $4—or worse. Meanwhile, YFI/USDT is on the cusp of falling further to $26k.

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Synthetix and Yearn Finance are sinking. If $7 falls, SNX/USDT may halve to $4—or worse. Meanwhile, YFI/USDT is on the cusp of falling further to $26k.

Yearn Finance (YFI)

The automated aggregator allows DeFi investors to draw maximum yields from various protocols. YFI is central to the platform.

Past Performance of YFI

The YFI/USDT is still under the shadow of sellers who dominated in the second half of May 2021.

Bears are in control, and liquidation across the board may flatten out attempts to revive bulls.

Presently, YFI is down nine percent against the USD and ETH on the last trading day.

READ  BaFin Eases Licensing Process For Foreign Crypto Custodians 

Day-Ahead and what to Expect

The path of least resistance is southwards.

Although Ethereum’s fundamentals might rejuvenate YFI/USDT price action, candlestick arrangement, and BTC weakness combine to deflate optimistic bulls.

YFI bear bars are banding along with the lower BB, signaling selling pressure below $40k and the middle BB.

YFI/USDT Technical Analysis

YFI Price Daily Chart for June 22

Losses of June 21 were perpendicular, pointing to sellers’ convictions.

Accordingly, every high may present a selling opportunity for YFI/USDT bears, targeting $26k or May 2021 lows.

Unexpected gains from spot levels, preferably with high trading volumes, reversing June 21 losses may trigger a revival with targets at $40k for YFI.

Conversely, further dumps firmly place YFI/USDT price action to sellers.

Synthetix (SNX)

The decentralized derivatives trading DeFi protocol uses SNX as its token. In addition, the platform plans to adopt Optimism as its Layer-2 scaling option.

READ  COTI and Avalanche (AVAX) Technical Analysis: What to Expect?

Past Performance of SNX

SNX sellers have reversed over 80 percent of gains made during the steep increase from November 2020 to 2021 peaks of February 2021.

Losses may continue considering the state of price action, favoring sellers.

SNX is down double-digits as of writing, falling 11 percent against the USD on the last trading day.

Meanwhile, trading volumes rose to $78 million, suggesting possible offloading.

Day-Ahead and what to Expect

SNX sellers, based on price action in the daily chart, are motoring ahead.

At spot rates, dips below $7 confirming June 21 draw-down may see another dump down towards $4—visible reaction points of November and December 2021.

SNX/USDT Technical Analysis

SNX Price Daily Chart for June 22

Confirmation of SNX/USDT bear bar of June 21 below $7 could cement sellers’ conviction.

READ  4 Reasons to Scrutinize BuyCrypto.today Before Using the Service

In that case, SNX prices may halve to $4.

Conversely, suppose prices find support at spot rates, reversing June 21 losses despite the intense selling pressure. In that case, SNX could lift off above $8 to $14 in the medium term.

#DeFi #SNX #SNX/USDT #Synthetix #Yearn.finance #YFI #YFI/USDT

Coinsmart. Beste Bitcoin-Börse in Europa
Source: https://www.cryptoknowmics.com/news/yearn-finance-yfi-and-synthetix-snx-technical-analysis-what-to-expect

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