A comprehensive overview of enterprise blockchain

Blockchain technology is often seen as a "cure-all" that can solve a wide range of problems because of its decentralized nature. However, blockchain is not an individual system but rather a protocol that allows different participants to transmit information by synchronizing various databases. This is accomplished by employing a distributed data structure that connects prior events in such a way that participants can easily validate the complete history, much like a digital ledger that numerous parties may view and trust to be correct and immutable. Businesses have the potential to benefit from distributed technology in several ways, that may include increased security, efficiency and cost-effectiveness. Many businesses in recent years are making their own enterprise versions of blockchain platforms, and others are working with their competitors to make blockchain solutions for their whole industry. The potential use cases for blockchain technology span across various sectors, such as trade finance, supply chain management, insurance, healthcare, digital identity management, financial services, and capital markets. 

In today's digital age, blockchain technology has emerged as a credible solution for enterprises facing myriad data management challenges. However, with each blockchain platform presenting its own unique set of tradeoffs and benefits, selecting the right option that aligns with the enterprise's specific needs can be a complex and challenging task.  A key to unlocking blockchain technology’s potential is an open-source collaborative software development model that helps ensure transparency, longevity, interoperability and support for its widespread commercial use. In this paper, we delve into the complexities of numerous enterprise blockchain technologies and present an extensive overview of the enterprise solutions available, highlighting the benefits and trade-offs. Additionally, to gain a deeper understanding of how participants reach consensus in a distributed blockchain setting, we encourage readers to refer to our article "A deeper dive into Consensus Mechanisms" for more information.¹

Blockchain technology has helped revolutionize the way we visualize data management and security. The technology is a distributed, shared ledger system that can operate as a single source of truth for data management and security. One of blockchain’s distinguishing features is its ability to create distributed networks that allow multiple parties to access, update and authenticate. Nonetheless, not all blockchain networks are created equal.

 

1. Permissionless blockchains
   
   1. Public blockchain: A public blockchain, also identified as a "trustless blockchain," is a decentralized, publicly accessible network that is similar to a city's public transportation system. Anyone can purchase a ticket and ride the bus or subway; similarly, anyone can participate in the network, validate transactions and generate new blocks by providing computing power or staking their cryptocurrency. Bitcoin and Ethereum are examples of public, permissionless blockchains. 
      
      A key advantage of permissionless blockchain networks is their transparency and decentralization, which helps ensure that no single entity controls the network. Since there is no single point of failure, allowing anyone to participate in the network allows for increased network security as it makes it more difficult for a single entity to control 51 percent of the computational power, which is a potential attack vector. Moreover, the use of cryptography helps safeguard the network's data storage integrity.
   
   
2. Permissioned blockchains
   
   We can divide permissioned blockchains into three categories based on the degree of customization and network configuration.
   
   1. Private blockchain: A private blockchain is a closed, participant-restricted network. Only authorized entities may participate in the network, validate transactions and generate new blocks. Private blockchain can be compared to a private transportation system, such as a chartered bus or train, to which only certain individuals or groups have access. Private blockchains are typically used within a company or organization but can also be used on a larger scale, such as a country's CBDC (Central Bank Digital Currency) and tokenized deposit infrastructure. They are also referred to as "enterprise blockchains" and are not open for public participation, meaning a specific group of participants control the computing power.
      
      A key advantage of permissioned blockchain networks include their capacity to offer a platform for private transactions, the ability to set and control governance and policies from a central location and the restricted access, which helps provide increased compliance with regulations. Typically, joining the network necessitates a verification procedure to identify the participant, who is then granted the appropriate permissions to access and conduct activities on the network. As a result, businesses and governments find them an attractive option around which to structure their solutions, as they can help control privacy and compliance. Examples of private blockchain networks include Hyperledger Fabric, Hyperledger Besu, Quorum and Corda Enterprise.
   2. Consortium or federated blockchain: A consortium blockchain, also known as a federated blockchain, is a type of distributed network that is governed by a group of organizations or entities. Unlike private blockchains, which are controlled by a single organization, consortium blockchains are governed by a pre-selected group of companies or institutions. One key difference between private blockchains and consortium blockchains is the level of control over the network. Consortium blockchain is comparable to a transportation network administered by multiple entities, such as a train system connecting multiple cities. The network is governed by multiple organizations or entities, which can be public entities such as government organizations and private organizations. Multiple municipalities may operate a train system this way. 
      
      A key advantage of consortium blockchains is that they help provide a platform for inter-organizational transactions. By pooling their resources and expertise, consortiums can create networks that are more efficient than what a single organization could achieve alone. Additionally, shared governance helps foster greater confidence among the participating organizations, which help lead to greater collaboration and innovation. Examples of consortium blockchain networks include Marco Polo Network and the Energy Web Foundation. 
   3. Hybrid or semi-private blockchain: A hybrid blockchain, also known as a semi-private blockchain, is a type of distributed network that combines features of both permissioned and permissionless blockchain architectures. Hybrid blockchain networks are highly customizable, allowing members to decide which transactions will be made public and who can participate in the network. Unlike other permissioned blockchains, hybrid blockchains strike a balance between security, privacy and openness by making some portions of the network private while leaving others public. This allows organizations to protect sensitive data while still benefiting from the advantages of public blockchains, such as transparency and immutability. Here, transactions and records are typically not made public, but they can be validated, if necessary, through smart contracts. This is in contrast to consortium blockchains, which rely on a pre-selected group of companies or institutions to control the consensus process. 
      
      A key advantage of hybrid blockchain networks is that they can provide an efficient platform for both public and private transactions. Hybrid blockchain is comparable to a transportation system that combines public and private options, such as a train system that consists of both regular trains and private VIP trains. Unlike other permissioned blockchains, which have predefined rules and restrictions, hybrid blockchains are highly customizable, making them more flexible. The Dragonchain platform is an example of hybrid blockchain networks.

Blockchain technology gives distributed networks many options that can be tailored to fit the needs of different industries and organizations. However, public blockchains face scalability issues and are limited in terms of privacy and permissioning. Ethereum, a widely adopted Layer 1 protocol, has seen significant enterprise adoption and the development of various use cases. As the benefits of blockchain technology become more apparent, an increasing number of businesses are experimenting with practical use cases that can be scaled using Ethereum. But Ethereum mainnet's throughput is only about 15 TPS (transactions per second), which is expected to get better with future upgrades. ² Additionally, the protocol does not natively support private transactions, which makes it difficult for businesses to use the Ethereum mainnet without making changes to run distributed applications that need privacy. Because of this, many businesses, like Hyperledger Besu, have turned to building client-side private transactions and permissioning that still use the Ethereum.

Ethereum clients are software applications that run on nodes and are specifically designed to handle Ethereum blockchain transactions. They make it possible for Ethereum nodes on the network to talk to each other and sync their states using peer-to-peer (P2P) networking. Given the nature of this architecture, organizations would need enterprise specific Ethereum clients that are compatible with the Ethereum mainnet to use on either the mainnet or a private network. Examples of such clients are Quorum and Hyperledger Besu, but some organizations may require more complex network setups, such as Hyperledger Fabric, depending on their use cases.

 

1. Hyperledger Fabric
   
   1. Overview - Hyperledger is a collection of open-source blockchain frameworks developed as part of a Linux Foundation initiative. There are multiple frameworks for blockchains in the Hyperledger family, and the project Fabric is highly modular and permissioned. A diverse development community that has grown to more than 35 organizations and 200 developers now maintain the Hyperledger Fabric project. A Fabric blockchain framework instance comprises a P2P network with nodes, a membership service provider (MSP), an ordering service, smart contracts or chaincode and the ledger.
   2. Privacy and permissioning features - Fabric is a permissioned blockchain platform that relies on its channel architecture and data structure to maintain privacy. Unlike other enterprise blockchain protocols, Fabric's design relies on a distinct type of node known as "endorsers/committers" or "peers" to handle transaction processing computation and state management. “Orderers”, on the other hand, are nodes responsible for establishing consensus, ordering transactions and enclosing them in blocks. Fabric also uses “channels,” which are defined as participants on a Fabric network creating a sub-network in which every member has visibility to a specific set of transactions. Accordingly, only nodes that participate in a channel have access to both the smart contract (chaincode) and the transacted data, preserving their privacy and confidentiality.
      
      Fabric offers two levels of transactional privacy. First, with message isolation via channels, a member who is not part of a channel is completely unaware of its existence. Organizations can use channels to separate transactions based on business units, departments or customers. This feature is particularly useful for organizations with multiple business units that must transact with one another but must keep separate ledgers for each.
      
      Second, private data collections enable organizations to share sensitive information with authorized parties via direct P2P communications. In this case, only the hashes for the private transaction inputs are shared with the ordering service and recorded in the ledger along with the transaction. This feature is useful in scenarios where certain data must be kept confidential and shared with specific parties. These Fabric features enable organizations to tailor their network configuration to their specific requirements, providing flexibility and control over data access, which is a significant advantage over other permissioned chains.
   3. Architecture
      
      Consensus mechanism: One of Fabric's strengths is its support for pluggable consensus protocols, enabling networks to use suitable protocols that meet their needs for high throughput and transaction finality. For example, when deployed within a single enterprise or operated by a trusted authority, a crash fault-tolerant (CFT) consensus protocol, which can tolerate a certain number of crashed or failed nodes, may be more appropriate, while a more traditional byzantine fault-tolerant (BFT) consensus protocol, which can additionally tolerate malicious or arbitrary behavior by nodes in the network, may be needed for a decentralized, multi-party use case. This modular approach makes Fabric highly adaptable and allows it to incorporate the best-in-class technology for each use case, while also future-proofing the technology for upcoming advancements in consensus mechanisms.
      
      Execution architecture: Most existing blockchain systems, from public to permissioned platforms, follow a traditional "order-execute" architecture. In this architecture, all transactions are executed sequentially by all nodes, and deterministic smart contracts are required to reach consensus. A deterministic smart contract is a type of smart contract that does not require any external information, such as from an oracle, to be executed. This is because each node on the network must be able to produce identical results for a method when given the same input. Thus, determinism is a critical requirement for smart contracts to ensure that the outcome of the contract is predictable and consistent across all nodes on the blockchain network. 
      
      Hyperledger Fabric takes a different approach, introducing a new architecture for executing transactions known as "execute-order-validate." This architecture distinguishes itself from other permissioned blockchains based on order execution by separating the transaction flow into three steps. First, transactions are executed and endorsed by the relevant parties. Second, transactions are ordered via a consensus protocol to ensure consistency across all nodes. Finally, transactions are validated against an application-specific endorsement policy before being committed to the ledger. This design offers greater flexibility, scalability and performance than traditional architectures. It also enables the use of standard programming languages, making it more accessible for businesses that already possess the necessary skill set to develop smart contracts without any additional training.
   4.  Use Cases
      
      Hyperledger Fabric is a versatile blockchain platform that has been successfully implemented in various use cases, including trade finance, supply chain management, insurance, healthcare, payments and digital identity credentials.³ In addition to the above use cases, below are notable examples of Fabric's successful implementation:
      
      1. Supply chain management: A blockchain-based food traceability system is being used to ensure transparency and tamper-proof data in the food supply chain. This system allows consumers to track the origin of their food, which helps to ensure food safety and quality.⁴
      2. B2B supplier onboarding: A blockchain-based solution is being used to simplify and secure the supplier onboarding process. The solution provides a secure and transparent record of all supplier data, which helps to improve efficiency and reduce costs.⁵
      3. Aviation ecommerce platform: An eCommerce platform for the aviation industry is being developed on Hyperledger Fabric. This platform aims to create a secure and transparent marketplace for trading used aircraft parts, thereby reducing procurement time.⁶
      4. Real estate: A blockchain-based platform is being used by a real estate association to provide better member services. The platform will help to improve the efficiency and transparency of the real estate market, and it will help to ensure that transactions are accurate and secure.⁷
      5. Global trade: A consortium of companies is leveraging a blockchain-based platform built on Hyperledger Fabric to enhance global trade efficiency. This platform aims to reduce costs, improve operational efficiency, and increase transparency in the shipping process.⁸
          
2. Hyperledger Besu
   
   1. Overview - Hyperledger Besu is a Java-based open-source client for Ethereum that allows developers to create smart contracts and decentralized applications on top of the Ethereum network. Its source code is publicly available, and subject to applicable license terms, anyone can contribute to it, report issues or suggest new features. The Apache License 2.0 governs the project, allowing for free use, modification and distribution of the software. Besu is designed to be interoperable with other networks and can function as a node in either a public Ethereum network or a private permissioned network. 
      
      Besu complies with the Ethereum Enterprise Alliance (EEA) specification, which specifies guidelines for enterprise solutions built on the Ethereum blockchain. The EEA specification, among other things, specifies requirements for security, scalability and privacy. Besu has implemented a wide range of EEA-compliant features, including permissioning and private transactions. Interledger integration between Hyperledger Besu and other blockchains such as Fabric, based on APIs (application programming interfaces) for actions such as atomic swaps, is an active area of study.
   2. Privacy and permissioning features - With a similar focus on privacy, Besu’s Private Transaction Manager (PTM) is a key feature that allows for network privacy. It encrypts transaction data, making it private and inaccessible to third parties. This includes the transaction content, sender and list of parties involved. The PTM also enables the creation of private smart contracts, which allow private transactions to be executed within the smart contract. This feature is especially useful for enterprise use cases where privacy is a top priority. To implement privacy, Besu employs Tessera, a PTM. Each Besu node that sends or receives private transactions must be accompanied by a Tessera node. Private transactions are routed from the Besu node to the Tessera node, which encrypts and distributes the private transaction directly (that is, point-to-point) to the Tessera nodes involved in the transaction. Each participant in a privacy network has its own Besu and Tessera nodes by default. 
      
      Due to security concerns, Besu client does not include built-in key management. To manage private keys, it instead uses third-party tools such as Ethereum-compatible wallets or EthSigner. EthSigner is a tool that allows users to access the key store and sign transactions using third-party services such as Hashicorp Vault. ⁹ Because private keys are not stored within the Besu client, this method ensures greater security in their handling, reducing the likelihood of unauthorized access or breaches. Furthermore, using external key management solutions provides greater flexibility and integration with existing infrastructure.
      
      Besu is a permissioned network that restricts access to only approved nodes and accounts. Account permissioning and node permissioning are two distinct approaches to access control:
      1. Account permissioning enables the prohibition of specific accounts from taking part in network activities. The network does this by compiling a list of authorized accounts, and it rejects any transactions coming from accounts that are not on the list. This method allows for a high level of control over network access and is useful in situations where certain individuals or organizations require special privileges or access to specific parts of the network.
      2. Node permissioning, on the other hand, limits which nodes can connect and participate in the network. Node permissioning is a function that allows you to restrict access to entire network nodes by creating a list of approved nodes. Nodes that are not on the list are prohibited from accessing the network. This function ensures that only authorized nodes can join and participate in the network, improving the overall security and access control of the network.
   3. Architecture
      
      Consensus mechanism: Besu implements a variety of consensus protocols, including QBFT (Quorum Byzantine Fault Tolerance), IBFT (Istanbul Byzantine Fault Tolerance) 2.0, and Clique, which are intended for use in permissioned networks where participants know and trust one another. These consensus protocols offer faster block times and higher transaction throughput, making them more appropriate for high-performance, private networks. The validators and signers are chosen by the network participants or are pre-authorized, ensuring that only trusted and authorized nodes can participate in the network, thereby enhancing security and control. 
   4. Use cases
      
      Hyperledger Besu is a platform that is not limited to any particular industry and has been successfully implemented in various sectors such as financial services, supply chain management, digital identity management and healthcare.³ These examples demonstrate that Hyperledger Besu can be used to develop a wide range of solutions across industries and use cases:
      1. A blockchain ecosystem is being developed on Hyperledger Besu to create the world's largest permissioned public blockchain for government use. The aim is to enhance the quality of life in Latin America and the Caribbean through digital identity, land registry, and supply chain traceability systems.¹⁰
      2. Another use case involves a financial services platform developed on Hyperledger Besu that aims to democratize financial benefits through blockchain. The platform includes features like a stablecoin, a decentralized exchange, a lending and borrowing platform, and a savings account, especially geared towards payments and DeFi (Decentralized Finance).¹¹
      3. Hyperledger Besu also finds application in logistics, where it is used to create a blockchain platform for tracking returnable transportation items (RTIs). This platform improves efficiency, reduces costs, and increases security by maintaining a secure and transparent record of RTI movements.¹²
      4. In the retail sector, a blockchain-based loyalty program built on Hyperledger Besu is being used to boost customer loyalty. Customers earn points for purchases made with participating businesses and can redeem these points for rewards such as discounts, free products, or travel. ¹³
          
3. Quorum
   
   1. Overview
      
      Quorum is an enterprise-grade permissioned blockchain platform that combines the public Ethereum community’s innovations with advanced features tailored to meet the specific requirements of corporate clients. J.P. Morgan & Chase (JPMC) founded the platform in 2016, and it supports private transactions and smart contract execution for banks and financial service providers. Liink, a solution by J.P. Morgan built on the Onyx platform and powered by Quorum, streamlines cross-border payments by eliminating frictions.
      
      ConsenSys acquired Quorum in August 2020 to expand its enterprise blockchain adoption services and enhance Quorum's position as a leading blockchain platform for enterprise use. One of the major differences between Quorum and Hyperledger Besu is that Quorum is a fork of the Ethereum codebase, while Hyperledger Besu is an Ethereum client developed under the Hyperledger umbrella. Quorum offers built-in privacy features such as private transactions, which can be useful for enterprise applications that require the security of confidential data. 
   2. Privacy and permissioning features
      
      In terms of privacy, some consortium network participants prefer to limit how much information they share or with whom they transact. Quorum helps ensure privacy by pairing a PTM, typically Tessera, with a member node. Tessera contains an enclave responsible for cryptographic functions. This enclave handles the storage and access of encrypted transaction data. Instead of directly exchanging information with other enclaves, the enclave sends encrypted payloads to other Tessera nodes, which then securely propagate these transactions throughout the network. As explained in the Hyperledger Besu section, the working relationship between the Quorum node and the Tessera node is similar. Permissioning entails a distributed network of trust across a blockchain network, with participants agreeing to abide by certain rules. If a participant violates these rules, the rest of the honest nodes in the network can address the violation, preventing any unauthorized additions to the blockchain. Quorum supports both node and account Permissioning, allowing only specific nodes and accounts to connect to the network. The Besu section explains both types of permissions.
      
      Quorum is currently experimenting with an added security feature known as zero-knowledge (ZK) cryptography. This advanced technology enables a verifier to confirm the truth of a statement about confidential information without revealing the information in question. The verification process follows a binary system—it's either confirmed or denied. Notably, the system performing the verification doesn't need to decrypt the data. This automated process minimizes the potential for human error, facilitating the secure sharing of sensitive information within the network without the risk of exposing it to malicious actors. 
   3. Architecture
      
      Consensus mechanism: Quorum is a blockchain platform that employs several consensus protocols, including QBFT, IBFT, Raft and Clique. These protocols are intended for networks in which participant identities are known and have an appropriate level of trust, such as permissioned consortium networks. Compared to the Ethereum mainnet's Proof of Stake (PoS) consensus, Quorum's consensus protocols offer faster block times and higher transaction throughput. In the case of the QBFT or IBFT consensus protocol, a specific threshold of network nodes serves as validators. These validators collaborate to reach consensus on transactions proposed by a lead validator node, providing BFT capabilities. With the Raft protocol, a leader node proposes the new block, while follower nodes vote and accept data (logs) from the leader.
      
      Gas-free network: Transactions consume computational resources, so they incur costs. The transaction cost is calculated by multiplying the amount of gas used by the price of gas. The account submitting the transaction pays the transaction cost in ETH on public Ethereum networks. In private networks, such as Quorum, network participants run the validators and do not need gas as an incentive. As a result, these networks typically remove or configure the gas price to be zero, resulting in free gas. Quorum operates as a free gas network by default, eliminating the need for a gas price.
   4.  Use cases
      
      Diverse industries are adopting Quorum blockchain for its privacy and permissioning capabilities. These examples illustrate the versatility of Quorum blockchain in enhancing the effectiveness, security and automation of a wide range of industries:
      
      
      1. JPMC Coin Systems leverages the Quorum platform to provide Blockchain Deposit Accounts. Additionally, Onyx Digital Assets utilizes Quorum to facilitate the tokenization and transfer of traditional financial assets. ¹⁴
      2. A pair of leading insurance companies have deployed Quorum's blockchain technology to streamline and speed up the auto subrogation claims process.¹⁵
      3. A healthcare blockchain consortium is utilizing Quorum to establish a secure and private network for healthcare data sharing, thereby improving care quality by providing healthcare providers with access to more comprehensive and accurate patient information.¹⁶
      4. Quorum is also being explored for emerging use cases, including digital identity management, demonstrating its potential for future applications.¹⁷

Choosing the right enterprise blockchain platform requires a thorough evaluation of a range of factors such as the technology's capabilities, suitability for enterprise and consortium use, deployment options, maturity, adoption by other enterprises and consortiums, licensing options and level of professional support available. To demonstrate which platform is best suited for a specific enterprise use case, we will compare the governance, network topology, smart contract development, consensus, security, scalability and transaction permissioning features of Hyperledger Fabric, Hyperledger Besu and Quorum.

Comparison of governance and support features in Hyperledger Fabric, Hyperledger Besu and Quorum

Comparison of network topology and composition in Hyperledger Fabric, Hyperledger Besu and Quorum

Comparison of network access and management in Hyperledger Fabric, Hyperledger Besu and Quorum

Comparison of smart contract implementation and development in Hyperledger Fabric, Hyperledger Besu and Quorum

Comparison of the consensus and protocol upgrade features in Hyperledger Fabric, Hyperledger Besu and Quorum

Comparison of security and interoperability features in Hyperledger Fabric, Hyperledger Besu and Quorum

Comparison of scalability and modularity in Hyperledger Fabric, Hyperledger Besu and Quorum

Comparison of transaction and permissioning in Hyperledger Fabric, Hyperledger Besu and Quorum

Each blockchain platform offers its own unique combination of tradeoffs and benefits. Choosing the right option that aligns with an enterprise's specific needs can be a complex and challenging task. To assist in this decision-making process, a flowchart can help identify the most appropriate blockchain platform based on a range of factors such as shared database requirements, desired level of security, privacy and interoperability. By answering a series of yes or no questions, organizations can use the flowchart as a preliminary step for initial assessment, applying further research to ultimately determine the most suitable blockchain platform for their specific use case (see the detailed table analysis presented earlier in this report). Figure 3 is evaluated based on the characteristics outlined in this report; other private or consortium blockchain networks with similar traits can be used for further exploration.

Blockchain technology offers businesses many ways to use distributed ledgers. Permissionless and permissioned blockchains offer different solutions based on specific requirements and use cases. Three of the most popular enterprise-grade blockchain platforms are Hyperledger Fabric, Hyperledger Besu and Quorum, each providing unique features and abilities that can assist businesses with their varying needs. As the global economy continues to grow, innovative solutions for B2B cross-border payments are emerging and providing significant benefits to banks and their customers, such as greater flexibility, transparency, predictability, compliance and data access. The reduction of fees associated with managing relationships with intermediary banks is a substantial advantage of implementing a multilateral cross-border payment system.  In 2019, Visa launched the B2B Connect platform, a first-of-its-kind solution based on Hyperledger Fabric. ²¹ The platform operates within a centrally managed, permissioned network where the identity of all participants is known. This structure allows for swift and secure processing of payments, reducing costs and simplifying the management of multiple accounts.

Hyperledger Fabric offers modularity, flexibility and privacy through its unique architecture and consensus mechanisms. Hyperledger Besu provides a robust platform for developing and deploying decentralized applications with the support of the Ethereum network in a privacy-preserving manner. Quorum, on the other hand, offers privacy through its use of the Tessera and its integration with the Ethereum ecosystem. Each of these three permissioned blockchains has unique traits and choosing the right platform for enterprise needs can be complex. This report aimed to explain the nuances of these blockchains' design and architecture in detail. The flowchart can help enterprises vet choices with further research.

As blockchain technology continues to evolve, it is crucial for enterprises to stay updated and evaluate the various platforms available to identify the one that best suits their needs. With the right implementation strategy, blockchain technology can help enterprises achieve new levels of efficiency, security and transparency, bringing transformative benefits to their operations.

Reach out to Visa Crypto at [email protected] to learn more about Visa’s involvement in the crypto ecosystem and our products we are currently building to help expand capabilities within blockchain payments. 

This article is part of a series of articles on blockchain ecosystem developments. Head over to Visa Crypto Thought Leadership for more consumer insights, best practices and innovative approaches to the blockchain through our research.

Disclaimer

These materials are provided for informational purposes only and should not be relied upon for marketing, legal, regulatory or other advice. Recommendations must be independently evaluated in light of your specific business needs and any applicable laws and regulations. Visa is not responsible for your use of these materials, best practice recommendations, or other information, including errors of any kind, contained in this document. All brand names, logos and/or trademarks are the property of their respective owners, are used for identification purposes only, and do not necessarily imply product endorsement or affiliation with Visa.

Footnotes