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Smart contract showdown: Hyperledger Fabric vs MultiChain vs Ethereum vs Corda

There’s more than one way to put code on a blockchain In most discussions about blockchains, it doesn’t take long for the notion of “smart contracts” to come up. In the popular imagination, smart contracts automate the execution of interparty interactions, without requiring a trusted intermediary. By expressing legal relationships in code rather than words,… Read more »

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There’s more than one way to put code on a blockchain

In most discussions about blockchains, it doesn’t take long for the notion of “smart contracts” to come up. In the popular imagination, smart contracts automate the execution of interparty interactions, without requiring a trusted intermediary. By expressing legal relationships in code rather than words, they promise to enable transactions to take place directly and without error, whether deliberate or not.

From a technical viewpoint, a smart contract is something more specific: computer code that lives on a blockchain and defines the rules for that chain’s transactions. This description sounds simple enough, but behind it lies a great deal of variation in how these rules are expressed, executed and validated. When choosing a blockchain platform for a new application, the question “Does this platform support smart contracts?” isn’t the right one to ask. Instead, we need to be asking: “What type of smart contracts does this platform support?”

In this article, my goal is to examine some of the major differences between smart contract approaches and the trade-offs they represent. I’ll do this by looking at four popular enterprise blockchain platforms which support some form of customized on-chain code. First, IBM’s Hyperledger Fabric, which calls its contracts “chaincode”. Second, our MultiChain platform, which introduces smart filters in version 2.0. Third, Ethereum (and its permissioned Quorum and Burrow spin-offs), which popularized the “smart contract” name. And finally, R3 Corda, which references “contracts” in its transactions. Despite all of the different terminology, ultimately all of these refer to the same thing – application-specific code that defines the rules of a chain.

Before going any further, I should warn the reader that much of the following content is technical in nature, and assumes some familiarity with general programming and database concepts. For good or bad, this cannot be avoided – without getting into the details it’s impossible to make an informed decision about whether to use a blockchain for a particular project, and (if so) the right type of blockchain to use.

Blockchain basics

Let’s begin with some context. Imagine an application that is shared by multiple organizations, which is based on an underlying database. In a traditional centralized architecture, this database is hosted and administered by a single party which all of the participants trust, even if they do not trust each other. Transactions which modify the database are initiated only by applications on this central party’s systems, often in response to messages received from the participants. The database simply does what it’s told because the application is implicitly trusted to only send it transactions that make sense.

Blockchains provide an alternative way of managing a shared database, without a trusted intermediary. In a blockchain, each participant runs a “node” that holds a copy of the database and independently processes the transactions which modify it. Participants are identified using public keys or “addresses”, each of which has a corresponding private key known only to the identity owner. While transactions can be created by any node, they are “digitally signed” by their initiator’s private key in order to prove their origin.

Nodes connect to each other in a peer-to-peer fashion, rapidly propagating transactions and the “blocks” in which they are timestamped and confirmed across the network. The blockchain itself is literally a chain of these blocks, which forms an ordered log of every historical transaction. A “consensus algorithm” is used to ensure that all nodes reach agreement on the content of the blockchain, without requiring centralized control. (Note that some of this description does not apply to Corda, in which each node has only a partial copy of the database and there is no global blockchain. We’ll talk more about that later on.)

In principle, any shared database application can be architected by using a blockchain at its core. But doing so creates a number of technical challenges which do not exist in a centralized scenario:

  • Transaction rules. If any participant can directly change the database, how do we ensure that they follow the application’s rules? What stops one user from corrupting the database’s contents in a self-serving way?
  • Determinism. Once these rules are defined, they will be applied multiple times by multiple nodes when processing transactions for their own copy of the database. How do we ensure that every node obtains exactly the same result?
  • Conflict prevention. With no central coordination, how do we deal with two transactions that each follow the application’s rules, but nonetheless conflict with each other? Conflicts can stem from a deliberate attempt to game the system, or be the innocent result of bad luck and timing.

So where do smart contracts, smart filters and chaincode come in? Their core purpose is to work with a blockchain’s underlying infrastructure in order to solve these challenges. Smart contracts are the decentralized equivalent of application code – instead of running in one central place, they run on multiple nodes in the blockchain, creating or validating the transactions which modify that database’s contents.

Let’s begin with transaction rules, the first of these challenges, and see how they are expressed in Fabric, MultiChain, Ethereum and Corda respectively.

Transaction rules

Transaction rules perform a specific function in blockchain-powered databases – restricting the transformations that can be performed on that database’s state. This is necessary because a blockchain’s transactions can be initiated by any of its participants, and these participants do not trust each other sufficiently to allow them to modify the database at will.

Let’s see two examples of why transaction rules are needed. First, imagine a blockchain designed to aggregate and timestamp PDF documents that are published by its participants. In this case, nobody should have the right to remove or change documents, since doing so would undermine the entire purpose of the system – document persistence. Second, consider a blockchain representing a shared financial ledger, which keeps track of the balances of its users. We cannot allow a participant to arbitrarily inflate their own balance, or take others’ money away.

Inputs and outputs

Our blockchain platforms rely on two broad approaches for expressing transaction rules. The first, which I call the “input–output model”, is used in MultiChain and Corda. Here, transactions explicitly list the database rows or “states” which they delete and create, forming a set of “inputs” and “outputs” respectively. Modifying a row is expressed as the equivalent operation of deleting that row and creating a new one in its place.

Since database rows are only deleted in inputs and only created in outputs, every input must “spend” a previous transaction’s output. The current state of the database is defined as the set of “unspent transaction outputs” or “UTXOs”, i.e. outputs from previous transactions which have not yet been used. Transactions may also contain additional information, called “metadata”, “commands” or “attachments”, which don’t become part of the database but help to define their meaning or purpose.

Given these three sets of inputs, outputs and metadata, the validity of a transaction in MultiChain or Corda is defined by some code which can perform arbitrary computations on those sets. This code can validate the transaction, or else return an error with a corresponding explanation. You can think of the input–output model as an automated “inspector” holding a checklist which ensures that transactions follow each and every rule. If the transaction fails any one of those checks, it will automatically be rejected by all of the nodes in the network.

It should be noted that, despite sharing the input–output model, MultiChain and Corda implement it very differently. In MultiChain, outputs can contain assets and/or data in JSON, text or binary format. The rules are defined in “transaction filters” or “stream filters”, which can be set to check all transactions, or only those involving particular assets or groupings of data. By contrast, a Corda output “state” is represented by an object in the Java or Kotlin programming language, with defined data fields. Corda’s rules are defined in “contracts” which are attached to specific states, and a state’s contract is only applied to transactions which contain that state in its inputs or outputs. This relates to Corda’s unusual visibility model, in which transactions can only be seen by their counterparties or those whose subsequent transactions they affect.

Contracts and messages

The second approach, which I call the “contract–message model”, is used in Hyperledger Fabric and Ethereum. Here, multiple “smart contracts” or “chaincodes” can be created on the blockchain, and each has its own database and associated code. A contract’s database can only be modified by its code, rather than directly by blockchain transactions. This design pattern is similar to the “encapsulation” of code and data in object-oriented programming.

With this model, a blockchain transaction begins as a message sent to a contract, with some optional parameters or data. The contract’s code is executed in reaction to the message and parameters, and is free to read and write its own database as part of that reaction. Contracts can also send messages to other contracts, but cannot access each other’s databases directly. In the language of relational databases, contracts act as enforced “stored procedures”, where all access to the database goes via some predefined code.

Both Fabric and Quorum, a variation on Ethereum, complicate this picture by allowing a network to define multiple “channels” or “private states”. The aim is to mitigate the problem of blockchain confidentiality by creating separate environments, each of which is only visible to a particular sub-group of participants. While this sounds promising in theory, in reality the contracts and data in each channel or private state are isolated from those in the others. As a result, in terms of smart contracts, these environments are equivalent to separate blockchains.

Example rules

Let’s see how to implement the transaction rules for a single-asset financial ledger with these two models. Each row in our ledger’s database has two columns, containing the owner’s address and the quantity of the asset owned. In the input–output model, transactions must satisfy two conditions:

  1. The total quantity of assets in a transaction’s outputs has to match the total in its inputs. This prevents users from creating or deleting money arbitrarily.
  2. Every transaction has to be signed by the owner of each of its inputs. This stops users from spending each other’s money without permission.

Taken together, these two conditions are all that is needed to create a simple but viable financial system.

In the contract–message model, the asset’s contract supports a “send payment” message, which takes three parameters: the sender’s address, recipient’s address, and quantity to be sent. In response, the contract executes the following four steps:

  1. Verify that the transaction was signed by the sender.
  2. Check that the sender has sufficient funds.
  3. Deduct the requested quantity from the sender’s row.
  4. Add that quantity to the recipient’s row.

If either of the checks in the first two steps fails, the contract will abort and no payment will be made.

So both the input–output and contract–message models are effective ways to define transaction rules and keep a shared database safe. Indeed, on a theoretical level, each of these models can be used to simulate the other. In practice however, the most appropriate model will depend on the application being built. Does each transaction affect few or many pieces of information? Do we need to be able to guarantee transaction independence? Does each piece of data have a clear owner or is there some global state to be shared?

It is beyond our scope here to explore how the answers should influence a choice between these two models. But as a general guideline, when developing a new blockchain application, it’s worth trying to express its transaction rules in both forms, and seeing which fits more naturally. The difference will express itself in terms of: (a) ease of programming, (b) storage requirements and throughput, and (c) speed of conflict detection. We’ll talk more about this last issue later on.

Built-in rules

When it comes to transaction rules, there is one way in which MultiChain specifically differs from Fabric, Ethereum and Corda. Unlike these other platforms, MultiChain has several built-in abstractions that provide some basic building blocks for blockchain-driven applications, without requiring developers to write their own code. These abstractions cover three areas that are commonly needed: (a) dynamic permissions, (b) transferrable assets, and (c) data storage.

For example, MultiChain manages permissions for connecting to the network, sending and receiving transactions, creating assets or streams, or controlling the permissions of other users. Multiple fungible assets can be issued, transferred, retired or exchanged safely and atomically. Any number of “streams” can be created on a chain, for publishing, indexing and retrieving on-chain or off-chain data in JSON, text or binary formats. All of the transaction rules for these abstractions are available out-of-the-box.

When developing an application on MultiChain, it’s possible to ignore this built-in functionality, and express transaction rules using smart filters only. However, smart filters are designed to work together with its built-in abstractions, by enabling their default behavior to be restricted in customized ways. For example, the permission for certain activities might be controlled by specific administrators, rather than the default behavior where any administrator will do. The transfer of certain assets can be limited by time or require additional approval above a certain amount. The data in a particular stream can be validated to ensure that it consists only of JSON structures with required fields and values.

In all of these cases, smart filters create additional requirements for transactions to be validated, but do not remove the simple rules that are built in. This can help address one of the key challenges in blockchain applications: the fact that a bug in some on-chain code can lead to disastrous consequences. We’ve seen endless examples of this problem in the public Ethereum blockchain, most famously in the Demise of The DAO and the Parity multisignature bugs. Broader surveys have found a large number of common vulnerabilities in Ethereum smart contracts that enable attackers to steal or freeze other peoples’ funds.

Of course, MultiChain smart filters may contain bugs too, but their consequences are more limited in scope. For example, the built-in asset rules prevent one user from spending another’s money, or accidentally making their own money disappear, no matter what other logic a smart filter contains. If a bug is found in a smart filter, it can be deactivated and replaced with a corrected version, while the ledger’s basic integrity is protected. Philosophically, MultiChain is closer to traditional database architectures, where the database platform provides a number of built-in abstractions, such as columns, tables, indexes and constraints. More powerful features such as triggers and stored procedures can optionally be coded up by application developers, in cases where they are actually needed.

Transaction rules Fabric MultiChain Ethereum Corda
Model Contract–message Input–output Contract–message Input–output
Built-ins None Permissions +
assets + streams
None None

Determinism

Let’s move on to the next part of our showdown. No matter which approach we choose, the custom transaction rules of a blockchain application are expressed as computer code written by application developers. And unlike centralized applications, this code is going to be executed more than one time and in more than one place for each transaction. This is because multiple blockchain nodes belonging to different participants have to each verify and/or execute that transaction for themselves.

This repeated and redundant code execution introduces a new requirement that is rarely found in centralized applications: determinism. In the context of computation, determinism means that a piece of code will always give the same answer for the same parameters, no matter where and when it is run. This is absolutely crucial for code that interacts with a blockchain because, without determinism, the consensus between the nodes on that chain can catastrophically break down.

Let’s see how this looks in practice, first in the input–output model. If two nodes have a different opinion about whether a transaction is valid, then one will accept a block containing that transaction and the other will not. Since every block explicitly links back to a previous block, this will create a permanent “fork” in the network, with one or more nodes not accepting the majority opinion about the entire blockchain’s contents from that point on. The nodes in the minority will be cut off from the database’s evolving state, and will no longer be able to effectively use the application.

Now let’s see what happens if consensus breaks down in the contract–message model. If two nodes have a different opinion about how a contract should respond to a particular message, this can lead to a difference in their databases’ contents. This in turn can affect the contract’s response to future messages, including messages it sends to other contracts. The end result is an increasing divergence between different nodes’ view of the database’s state. (The “state root” field in Ethereum blocks ensures that any difference in contracts’ responses leads immediately to a fully catastrophic blockchain fork, rather than risking staying hidden for a period of time.)

Sources of non-determinism

So non-determinism in blockchain code is clearly a problem. But if the basic building blocks of computation, such as arithmetic, are deterministic, what do we have to worry about? Well, it turns out, quite a few things:

  • Most obviously, random number generators, since by definition these are designed to produce a different result every time.
  • Checking the current time, since nodes won’t be processing transactions at exactly the same time, and in any event their clocks may be out of sync. (It’s still possible to implement time-dependent rules by making reference to timestamps within the blockchain itself.)
  • Querying external resources such as the Internet, disk files, or other programs running on a computer. These resources cannot be guaranteed to always give the same response, and may become unavailable.
  • Running multiple pieces of code in parallel “threads”, since this leads to a “race condition” where the order in which these processes finish cannot be predicted.
  • Performing any floating point calculations which can give even minutely different answers on different computer processor architectures.

Our four blockchain platforms employ several different approaches to avoiding these pitfalls.

Deterministic execution

Let’s start with Ethereum, since its approach is the most “pure”. Ethereum contracts are expressed in a special-purpose format called “Ethereum bytecode”, which is executed by the Ethereum Virtual Machine (“EVM”). Programmers do not write bytecode directly, but rather generate or “compile” it from a JavaScript-like programming language called Solidity. (Other languages used to be available but have since been deprecated.) Determinism is guaranteed by the fact that Solidity and Ethereum bytecode cannot encode any non-deterministic operations – it’s that simple.

MultiChain filters and Corda contracts choose a different approach, by adapting existing programming languages and runtime environments. MultiChain uses JavaScript running in Google’s V8 engine, which also forms the core of the Chrome browser and the Node.js platform, but with sources of non-determinism disabled. Similarly, Corda uses Java or Kotlin, both of which are compiled to “Java bytecode” which executes within a Java Virtual Machine (“JVM”). For now, Corda uses Oracle’s standard non-deterministic JVM, but work is under way to integrate a deterministic version. In the meantime, Corda contract developers must take care not to allow non-determinism in their code.

How does Ethereum’s purism compare with the evolutionary approach taken by MultiChain and Corda? The main advantage for Ethereum is risk minimization – a built-for-purpose virtual machine is less likely to contain an inadvertent source of non-determinism. While any such oversight could be fixed by a software update, it would be disruptive to any chain that was unlucky enough to encounter it. Ethereum’s problem, however, is that Solidity and the EVM constitute a tiny and nascent ecosystem in the wider context of programming languages and runtime environments. By comparison, JavaScript and Java are the top two languages on Github, run on billions of digital devices, and have runtimes that have been optimized over decades. Presumably this is why the public Ethereum blockchain is considering a transition to eWASM, a deterministic fork of the emerging WebAssembly standard.

Determinism by endorsement

When it comes to determinism, Hyperledger Fabric adopts a completely different approach. In Fabric, when a “client” node wants to send a message to some chaincode, it first sends that message to some “endorser” nodes. Each of these nodes executes the chaincode independently, forming an opinion of the message’s effect on that chaincode’s database. These opinions are sent back to the client together with a digital signature which constitutes a formal “endorsement”. If the client receives enough endorsements of the intended outcome, it creates a transaction containing those endorsements, and broadcasts it for inclusion in the chain.

In order to guarantee determinism, each piece of chaincode has an “endorsement policy” which defines exactly what level of approval is required in order to render its transactions valid. For example, one chaincode’s policy might state that endorsements are required from at least half of the blockchain’s nodes. Another might require an endorsement from any one of three trusted parties. Either way, every node can independently check if the necessary endorsements were received.

To clarify the difference, determinism in most blockchain platforms is based on the question: “What is the result of running this code on this data?” – and we need to be absolutely sure that every node will answer this question identically. By contrast, determinism in Fabric is based on a different question: “Do enough endorsers agree on the result of running this code on this data?” Answering that is a rather simple matter of counting, and there’s no room for non-determinism to creep in.

Fabric’s determinism-by-endorsement has a number of interesting consequences. First, chaincode can be written in many different programming languages, since these don’t need to be adapted for determinism (Go, Java and JavaScript are currently supported). Second, chaincode can be hidden from some of a blockchain’s participants, since it only needs to be executed by clients and endorsers (the database itself is globally visible). Finally and most notably, Fabric chaincode can do things that are forbidden in other blockchain environments, such as checking the weather using an online web API. In the worst case, where every endorser gets a different answer from this API, the client will fail to obtain enough endorsements for any particular outcome, and no transaction will take place. (It should be noted that Fabric team members still recommend using deterministic logic inside chaincode, in order to avoid surprises.)

What price does Fabric pay for this flexibility? If the purpose of a blockchain is to remove intermediaries from a shared database-driven application, then Fabric’s reliance on endorsers takes a big step away from that goal. For the participants in the chain, it is no longer enough to follow the chaincode’s rules – they also need certain other nodes to agree that they have done so. Even worse, a malicious subset of endorsers could approve database changes that do not follow chaincode at all. This gives endorsers much more power than the validators in regular blockchains, who can censor transactions but cannot violate the blockchain’s rules. Blockchain application developers must decide whether this trade-off makes sense in their particular case.

Determinism Fabric MultiChain Ethereum Corda
Model Endorsements Adapted runtime Purpose-built VM Adapted runtime
Languages Go + Java + JavaScript JavaScript Solidity Java + Kotlin
Code visibility Counterparties +
endorsers
Blockchain Blockchain Counterparties +
dependents
Enforced No Yes Yes No (for now)

Conflict prevention

So far, we’ve discussed how different blockchain platforms express transaction rules in code, and how they deterministically ensure that every node applies those rules identically. Now it’s time to talk about a third aspect of our showdown: How does each platform deal with the possibility that two transactions, which are valid in and of themselves, conflict with each other? In the simplest example, imagine that Alice has $10 in a financial ledger and broadcasts two transactions – one sending $8 to Bob, and the other sending $7 to Charlie. Clearly, only one of these transactions can be allowed to succeed.

Two models

We can begin by grouping MultiChain’s and Corda’s approach to this problem together. As described earlier, both of these use an input–output model for representing transactions and their rules, in which each transaction input spends a previous transaction output. This leads to a simple principle for preventing conflicts: Every output can only be spent once. MultiChain filters and Corda contracts can rely on their respective platforms to enforce this restriction absolutely. Since Alice’s $10 is represented by a previous transaction output, this single-spend rule automatically stops her sending it to both Bob and Charlie.

Despite this similarity, it’s important to point out a key difference in how MultiChain and Corda prevent conflicts. In MultiChain, every node sees every transaction and so can independently verify that each output is only spent once. Any transaction which performs a double spend against a previously confirmed transaction will be instantly and automatically rejected. By contrast, in Corda there is no global blockchain, so “notaries” are required to prevent these double spends. Every Corda output state is assigned to a notary, who has to sign any transaction spending that output, confirming it has not been spent before. A blockchain’s participants must trust notaries to follow this rule honestly, and malicious notaries can cause havoc at will. As with endorsements in Fabric, this “single-spend as a service” design has advantages in terms of confidentiality but reintroduces intermediaries, going against the blockchain grain. (It’s important to clarify that Corda notaries can be run by groups of participants using a consensus algorithm, so the integrity of the ledger can still be protected against individual bad actors).

Let’s move on to Ethereum. To recall, Ethereum uses contracts and messages rather than inputs and outputs. As a result, transaction conflicts such as Alice’s two payments are not immediately visible to the blockchain engine. Instead, they are detected and blocked by the contract which processes the transactions, after their order is confirmed on the chain. When processing each of Alice’s payments, the contract verifies whether her balance is sufficient. If the transaction paying $8 to Bob comes first, it will be processed as usual, leaving Alice with $2 in her account. As a result, when the contract processes the second transaction paying $7 to Charlie, it sees that Alice lacks the necessary funds and the transaction aborts.

Outputs vs contracts

So far we’ve seen two different techniques for preventing conflicting transactions – single-spend outputs in MultiChain and Corda, and contract-based verification in Ethereum. So which is better?

In order to help answer this question, let’s consider an example “1-of-2 multisignature” account which holds $100 on behalf of Gavin and Helen, and allows either of them to spend that money independently. Gavin instructs his application to pay $80 to Donna, and a few seconds later, Helen wants to send $40 to Edward. Since there are insufficient funds for both payments, these transactions would inevitably conflict. In the event that both transactions are broadcast, the outcome will be determined by whichever makes it first into the chain. Note that unlike Alice’s example, this conflict is accidental, since no one is trying to break the application’s rules – they simply had unlucky timing.

In considering the likelihood of this conflict occurring, the key question is this: After Gavin sends out his transaction, how long will it take Helen’s node to know that her payment might fail? The shorter this period is, the more likely Helen is to be stopped from attempting that payment, saving her and her application from a subsequent surprise.

With the input–output model, any conflict between transactions is directly visible to the blockchain platform, since the two transactions will be explicitly attempting to spend the same previous output. In MultiChain, this happens as soon as Gavin’s transaction has propagated to Helen’s node, usually in a second or less. In Corda, the output’s notary will refuse the request to sign Helen’s transaction, since it has already signed Gavin’s, so Helen will instantly know that her payment will fail. (Although if the Corda notary is itself distributed, she may have to wait a few seconds for a reply.) Either way, there is no need to wait for a transaction to be confirmed and ordered in the blockchain.

What about Ethereum’s model? In this case, there is no immediate way for the blockchain platform to know that a conflict will occur. While Helen’s node may see Gavin’s transaction on the network, it cannot know how this will affect Helen’s own transaction, since from its perspective these are simply two messages being sent to the same contract. Perhaps ten seconds later, once the final ordering of the conflicting transactions is confirmed on the blockchain, Helen’s node will recalculate the actual instead of the expected outcome, and her application will update its display accordingly. In the meantime, both Gavin and Helen will be left in the dark.

But we shouldn’t conclude from this that the input–output model always works best. Consider a variation on our example scenario, where both Gavin and Helen request smaller $40 payments from the original balance of $100, at exactly the same time. In the input–output model these transactions would conflict, since they are both spending the same database row containing that $100, and only one of the payments would succeed. But in Ethereum, both transactions would be successfully processed, irrespective of their final order, since the account contains sufficient funds for both. In this case, Ethereum more faithfully fulfills Gavin’s and Helen’s intentions.

Read-write sets

Finally, let’s talk about Fabric, whose endorsement-based approach is a hybrid of these two techniques. As explained earlier, when a Fabric “client” node wants to send a message to a contract, it first asks some endorsing nodes to execute that message on its behalf. The endorsing nodes do so in a similar way to Ethereum – running the contract against their local database – but this process is observed rather than immediately applied. Each endorser records the set of rows that would be read and written, noting also the exact version of those rows at that point in time. This “read-write set” of versioned rows is explicitly referenced in the endorsement, and included in the transaction which the client broadcasts.

Conflicts between Fabric transactions are resolved once their order is finalized in the chain. Every node processes each transaction independently, checking endorsement policies and applying the database changes specified. However, if a transaction reads or writes a database row version that has already been modified by a previous transaction, then that second transaction is ignored. To go back to Alice’s conflicting payments to Bob and Charlie, both of these transactions will read and modify the same row version, containing the $10 with which Alice started. So the second transaction will be safely and automatically aborted.

Fabric’s approach to conflict resolution works just fine, but in terms of performance and flexibility it combines the worst of the previous two models. Because endorsements convert transactions into specific read-write sets, Gavin and Helen’s simultaneous but compatible $40 payments would lead to a conflict that Ethereum avoids. However, Fabric does not gain the speed advantage of the input–output model, since endorsers execute contracts against the most recent version of the database confirmed by the blockchain, ignoring unconfirmed transactions. So if Helen initiates her payment a few seconds after Gavin, but before Gavin’s has been confirmed on the blockchain, Fabric will create conflicting transactions that a pure input–output model avoids.

Conflict prevention Fabric MultiChain Ethereum Corda
Model Read-write sets Single spend Contract checks Single spend
Verification Independent Independent Independent Trusted notaries
Speed ~10s (confirmation) ~1s (propagation) ~10s (confirmation) 0~5s (notary)

A complex choice

In this piece, we reviewed many of the different ways in which Corda, Ethereum, Fabric and MultiChain address the key challenges of “smart contracts”, or application code that is embedded in a blockchain. And each platform has different answers to our three core questions: How are transaction rules represented? How is code executed deterministically? And how do we prevent conflicts?

So who is the winner of our smart contract showdown? It should be obvious by now that there is no simple answer. Each platform represents a complex multi-way trade-off between flexibility, simplicity, performance, disintermediation, safety and confidentiality. So the choice of platform for a particular application has to begin with a detailed understanding of that application’s trust model, the types of transactions it involves, and their likely patterns of conflict. If you find someone pushing a specific smart contract solution before they know the answers to these questions, I suggest politely but firmly insisting that they adopt a “smarter” approach.

 

Please post any comments on LinkedIn.

 

Source: https://www.multichain.com/blog/2018/12/smart-contract-showdown/

Blockchain

Coinbase finally releases a timeline for listing Dogecoin

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Since Coinbase’s direct listing, it released the transcripts of its Q1 Earnings Call. During the call, the company addressed its plans of listing Dogecoin (DOGE), thanks to its ever-rising demand.

Coinbase‘s CEO Brian Armstrong talked about the exchange’s plans for the memecoin. He stated:

“So, to answer your question directly, we plan to list DOGE in the next six to eight weeks. And then more broadly, we’re going to be focused on how we can accelerate asset addition in the future.”

With regard to queries on what parameters were used to qualify various coins or tokens to add to the exchange and why there weren’t more choices? Armstrong stated:

I think there’s going to be millions of different crypto assets out there, especially as we see new assets being created for new companies being created and there’s even NFT’s and individuals who are tokenizing their time and so in a world where there’s going to be millions and millions of these crypto assets out there, we get this question a lot, how are you deciding, which ones to add, and how can you accelerate it?

Without directly alluding to XRP, the digital asset that has been entangled in a legal battle with the SEC, Coinbase CEO also stated that Coinbase had worked with CRC to create a regulatory framework for coins. He added:

So, today, we use a number of factors, we look at cybersecurity around the coin to make sure that there’s not going to be an issue that would cause customer loss. We also look at it from a legal point of view and a compliance point of view. There’s various concerns out there about securities, for instance, and we’ve worked with things like the Crypto Rating Council to help create clear regulatory frameworks for this.

Data from ICO Analytics stated that the total web traffic for crypto exchanges had increased by 43% over the past month.


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Source: https://ambcrypto.com/coinbase-finally-releases-a-timeline-for-listing-dogecoin

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Blockchain

Inflation winds stiffen as Bitcoin ballast on balance sheets proves its value

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As corporate finance leaders prepare to set sail into the post-COVID-19 world amid inflation storm warnings, an increasing number of corporations are taking stock of their treasury reserve holdings. If the worst happens, and the dollar and other reserve currencies weaken, are they sure that all their balance-sheet cash is lashed down securely?

It surely hasn’t escaped their notice, after all, that a number of public companies that “joined” Bitcoin (BTC) in a big way over the past year recently broadcast strong Q1 2021 earnings. Square, which holds $472 million worth of BTC, for instance, reported a quarterly gross profit increase of 79% year-over-year, doubling analysts’ expectations. While Tesla, which plunked down $1.5 billion — 8% of its cash — into BTC in February, posted record earnings with revenues surging 74%. MicroStrategy, which made Bitcoin its primary corporate reserve in 2020, notched a 10% gain in Q1 revenues.

“If inflation picks up, or even if it doesn’t, and more companies decide to diversify some small portion of their cash balances into bitcoin instead of cash, then the current relative trickle into bitcoin would become a torrent,” wrote storied investor Bill Miller in a market letter earlier this year. Already, “companies such as Square, MassMutual, and MicroStrategy have moved cash into bitcoin rather than have guaranteed losses on cash held on their balance sheet,” he added.

Elsewhere, Ark Investments commented in a company newsletter: “Microstrategy, Square, and now Tesla are showing public companies the way to add bitcoin as a legitimate alternative to cash on their balance sheets.”

But Bitcoin remains a volatile asset — as the most recent BTC price drop to $46,000 reminded users again — so maybe its embrace by corporate treasurers is really just a short-term happenstance? On the other hand, if the trend does have legs, is it really appropriate for all companies? If so, at what level of allocation is appropriate?

Overall, what does this say about the global economy if public firms now look to a 12-year-old digital currency to keep its cash stockpiles liquid and secure?

A longer-term trend or seasonal fashion?

“I do not view this as a fad,” Paul Cappelli, a portfolio manager at Galaxy Fund Management, told Cointelegraph. Bitcoin’s “inelastic supply curve and deflationary issuance schedule” make it a “compelling hedge against inflation and poor monetary policies that could lead to cash positions becoming devalued over time,” he told Cointelegraph, predicting:

“Corporations will continue to use Bitcoin as one of the tools available to preserve the value of their balance sheets.”

David Grider, lead digital asset strategist at Fundstrat, informed Cointelegraph that as crypto becomes more mainstream, he expects to see “more corporates holding crypto for legitimate business purposes.” Exchanges could hold it as inventory, tech companies might use it to stake tokens and participate in networks, while multinational corporations could accept it for payments.

“I expect two types of companies to consider early adoption of crypto — ones led by leaders who are strong believers in crypto, as well as companies that may have unique cross-border needs that are a good fit for Bitcoin transfers,” Gil Luria, director of research at D.A. Davidson & Co., told Cointelegraph.

If so, doesn’t this represent a sea change for corporate finance officers? “When I did my treasury exams, the thing we were told as number one objective is to guarantee security and liquidity of the balance sheet,” Graham Robinson, a partner in international tax and treasury at PricewaterhouseCoopers and adviser to the United Kingdom’s Association for Corporate Treasurers, told Reuters. BTC with its volatility might simply not fit the bill.

If Bitcoin were to be used as a corporate treasury reserve, and its price plunged, that company might not be able to meet its working capital requirements, noted Robert Willens, adjunct professor of Columbia Business School, in January, when he described it as “a high-risk, high-reward strategy.”

Has Willens changed his views? “I still believe it is a high risk/high reward strategy,” he told Cointelegraph, acknowledging that “lately, the rewards have far outweighed the risks.” He does see more firms following the lead of Tesla and Square, “as crypto investments become more ‘respectable’ and emerge as a viable outlet for corporate cash balances.” Asked who might lead the way, Willens answered:

“I think companies with iconoclastic leaders — not necessarily confined to a particular industry — would be the most likely to take the plunge and commit a decent amount of the corporation’s cash balances in crypto.”

Fundstrat’s Grider, citing the OTC trading firm Genesis’ Capital trading data, told Cointelegraph that more corporations may be buying crypto than has been reported in earnings statements. The Genesis Q1 2021 “Market Observations Report,” for example, reported a striking jump in “corporates’” share of crypto trading volume to ~27% from ~0% in the quarters prior. “As corporate clients began buying bitcoin for their treasuries in Q1, our ratios shifted,” noted Genesis.

Tesla allocated 8% — Is it too much?

Assuming that a company believes that crypto should be part of its treasury reserves, how much should it actually allocate? Last year, Cappelli told Cointelegraph that an investment of 50 basis points to 2% of reserves was about right, given crypto’s volatility. But since then, crypto prices have skyrocketed, and Tesla allocated a whopping 8% — or $1.5 billion — to its corporate cash reserves. Is the recommended allocation growing?

“I don’t think there’s a bright-line rule that we can apply here across the board,” Willens told Cointelegraph, “but I think something well north of 2% would be appropriate — perhaps as much as 8%–10% might even be acceptable.”

“It will all depend on the company,” Cappelli said this past week. “Corporations manage their balance sheets to fund operations and maintain a certain amount of liquidity.” Bitcoin is still a very volatile asset, “so while it does provide a hedge against inflation, it does come with a certain amount of market risk. I’d be very surprised to see a company allocation much more than a ballpark of 5% currently, but that may change over time.”

Still, what about Robinson’s contention that a corporate treasurer’s job is to guarantee liquidity and security of the balance sheet — and could Bitcoin not do that?

“If you think about crypto purely as cash, it is still very volatile relative to the dollar,” Grider told Cointelegraph. “But some assets like Bitcoin are becoming less volatile lately, and we are seeing strong liquidity emerge in crypto, which is encouraging.”

One way a firm could think about holding crypto is as an alternative to cash, continued Grider, “but you can also think about it like inventory or a marketable securities investment or an intangible long-term asset. That means even if not an ideal treasury asset in all respects, corporates could still hold crypto for other reasons,” such as:

“Certain incumbent businesses could buy crypto as a hedge against tech disruption, just like doing M&A of a competing startup.”

“I think the liquidity concern is a valid one,” responded Willens, “but limiting the investment to 8%–10% of the investible funds ought to insulate treasurers from criticism since the balance of the funds would be deployed in cash and cash equivalents with a readily realizable value.”

There is a sizing exercise that occurs for every investment, added Capelli, and “taking all balance sheet investments into account” is part of any corporate treasurer’s or chief investment officer’s job. Meanwhile, Luria declared that “crypto assets are liquid enough that this should not be a constraint.”

A more significant disincentive to using crypto as a corporate treasury reserve, in Willens’ view, may be the accounting treatment to which it is subjected at present — i.e., “the odd way investments in crypto are accounted for — they are treated as ‘indefinite-lived intangible assets,’ and thus any declines in the value of the asset must be reflected in income from continuing operations, whereas price increases cannot be so reflected.” He described this “unfavorable accounting treatment […] as the most unattractive aspect of an investment therein.”

A “tectonic shift” in global finance?

All in all, the current monetary environment has raised serious corporate concerns about inflation and the continued strength of the United States dollar. It should not be surprising, as Grider said, “that corporations would become more open to alternatives like crypto.”

But something even larger may be going on. As Perianne Boring noted recently in the New York Times, a “tectonic shift” may be underway in global finance thanks to cryptocurrency. “Digital assets have brought forth a new paradigm in global finance,” concurred Cappelli, though we are still in the very early stages:

“With every cycle, there are always pockets of froth, but structurally, what we have seen built over the last few years certainly provides a strong foundation for this new asset class.”

Coinsmart. Beste Bitcoin-Börse in Europa
Source: https://cointelegraph.com/news/inflation-winds-stiffen-as-bitcoin-ballast-on-balance-sheets-proves-its-value

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Why Tesla not accepting Bitcoin is the perfect ‘Ad campaign’ for it

Republished by Plato

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One public tweet that can have such catastrophic repercussions on an asset’s price is not something we hear on an everyday basis. Well, if you’re Elon Musk then it’s a completely different story. This precisely was the case with BTC’s most recent plummet in the market post Tesla’s announcement.

Various different exchanges saw an abrupt incline in the selling pressure, indicating a growing bearish trend. The cascading effect of Musk’s tweet has brought into question BTC’s uncorrelated status and its near-term price trajectory.

CIO of Blackrock, Rick Rieder shared his optimism about this ‘interesting asset’ in the latest CNBC’s Squawk Box interview. He stated:

“Bitcoin is an interesting asset. It is one that has not reached maturity yet.”

Although he acknowledged the challenges the asset faces – volatility and carbon footprint being the main obstacles, the senior executive remained bullish on the asset. He added:

“I think it’s durable. I think it will be part of the investment arena for years to come … but these challenges are real. They will be overcome over time.”

A Pompliano, a veteran bitcoin bull, too opined on the asset’s recent obstacles, namely the bad PR it’s facing thanks to Tesla.

He spoke about the ‘Streisand effect.’ In an additional tweet, he wrote:

“More people will be buying Bitcoin because of Elon Musk’s comments. This is the Streisand effect. Stop the madness and pay attention to the facts. Bitcoin isn’t going anywhere.”

But what exactly is the significance of this effect? Ever heard of the adage ‘There is no such thing as bad publicity?’ Stats on the subsequent tweets show that these hashtags were trending.

Source: Trendsmap

Another real-life example can be seen in India, where a looming threat of a crypto ban has resulted in a surge in interest.

Speculations surrounding the ban have actually increased the number of people investing in crypto. Something which was pointed out by CZ Binance in a recent ET tech interview. He stated:

“At least from what our data from India shows, it actually causes more people to invest in crypto because they want to get it before the ban comes in,”

Source: Google trends


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Coinsmart. Beste Bitcoin-Börse in Europa
Source: https://ambcrypto.com/why-tesla-not-accepting-bitcoin-is-the-perfect-ad-campaign-for-it

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