If you’ve been following blockchain technology, you’ve likely heard about smart contracts. But do you know what a smart contract is? These contracts could change how we do business and trade assets.
This guide explains how smart contracts work, their benefits, and their applications. Whether you’re a business owner, investor, or blockchain enthusiast, this technology deserves your attention.
What are Smart Contracts?
Smart contracts are self-executing computer programs that enforce contract terms automatically. They use blockchain technology for decentralised and transparent execution and verification.
Nick Szabo, a computer scientist, introduced smart contracts in 1994. He described them as electronic protocols that could automatically enforce contract terms without intermediaries.
Smart contracts use blockchain to create a decentralised, transparent system for contract execution and verification. Each contract is stored on a blockchain, maintaining a clear transaction record.
Once deployed on a blockchain, a smart contract can execute automatically when specific conditions are met. These conditions are predefined in the smart contract code and may include a specific date, cryptocurrency transfer, or task completion.
Types of Smart Contracts
Smart contracts are divided into three types: legal contracts, decentralised autonomous organisations (DAOs), and logic contracts. We will explain each in more detail.
Smart Legal Contracts
Smart contracts are legally binding and work like traditional contracts: “If this happens, then this will happen.” However, because they are on the blockchain, they cannot be changed, offering more transparency than traditional documents.
Parties use digital signatures to execute contracts. If certain conditions are met, such as making a payment when a deadline is reached, these contracts can be automatically executed. Not complying can lead to serious legal consequences.
Decentralised Autonomous Organisations (DAOs)
DAOs are groups governed by a smart contract that provides voting rights. They are blockchain-based organisations with a shared goal. There is no executive or president. Rules in the contract’s code determine the organisation’s operations and fund allocation.
Application Logic Contracts
ALCs, or application logic contracts, contain code that stays in sync with other blockchain contracts. They enable interactions between devices, such as IoT or blockchain integration. Unlike other smart contracts, these are signed between machines and other contracts, not humans or organisations.
Benefits of Smart Contracts
Recordkeeping
Smart contracts improve recordkeeping by offering secure, tamper-proof data storage. Every transaction within the contract is documented on the blockchain, creating an accurate and immutable ledger. This feature makes audit services more efficient and reliable. It also reduces the risk of fraud and human error. Consequently, businesses can trust the integrity of their contract data.
Autonomy
Smart contracts automate agreement execution, eliminating intermediaries and reducing admin tasks. This saves time and minimises human error. Smart contracts can trigger payments and track goods in supply chain management, ensuring transparency and efficiency.
Reduce Fraud
Smart contracts use blockchain technology, offering a secure and tamper-proof environment. Blockchain’s immutability means that once deployed, a contract cannot be changed or manipulated, improving security and lowering the risk of fraud or unauthorised changes.
Cost-Efficiency
Smart contracts cut costs by removing intermediaries and automating processes. In real estate, they streamline property transactions and eliminate the need for expensive lawyers or brokers.
How Do Smart Contracts Work?
A smart contract is a binding agreement between two parties, just like any other contract. It uses code to leverage the benefits of blockchain technology, providing more efficiency, transparency, and privacy. Smart contracts operate with simple “if/when…then…” statements written in code on the blockchain. Here are the steps needed for smart contracts to function.
Parties Agree to Terms and Conditions
The parties conducting business or exchanging products or services must agree to the terms and conditions. They must decide how the smart contract will work and the criteria required for the agreement to be completed.
The Smart Contract Is Created
Participants in a transaction can create a smart contract themselves or work with a smart contract provider. The contract’s terms are coded in a programming language. At this stage, thoroughly verifying the contract’s security is crucial.
The Smart Contract Is Deployed
Once the contract is finalised, it must be published on the blockchain. The smart contract is uploaded to the blockchain like regular crypto transactions, with the code inserted into the data field. After verifying the transaction, it becomes active on the blockchain and cannot be changed or reversed.
Triggering Conditions Are Met
A smart contract operates by monitoring the blockchain or another reliable source for specific conditions or prompts. These triggers can be anything that can be digitally verified, like a date reached or a payment made.
The Smart Contract Is Executed
When the trigger parameters are met, the smart contract activates according to the “if/when…then…” statement. This can include one or more actions, such as transferring funds to a vendor or recording the buyer’s ownership of an asset.
The Contract Result Is Recorded on the Blockchain
Contract execution results are quickly published on the blockchain. The system verifies the actions taken, logs their completion as an exchange, and stores the agreement on the blockchain. This document is always accessible.
Use of Smart Contracts
Digital Identity Cards
Users can store reputational data and digital assets on smart contracts to create a digital ID card. When linked to multiple online services, these smart contracts allow others to learn about individuals without revealing their true identities.
For example, lenders can use credit scores in these contracts to verify loan applicants without demographic profiling or discrimination. Candidates can also share resumes without risking gender bias in hiring.
Supply Chain Management
Hybrid contracts automate payments, monitor rule compliance, and track items in the supply chain. The off-chain component stores private information like invoices. The on-chain component executes the contract and initiates payments based on set criteria.
Healthcare
Blockchain can store encrypted health records with a private key. Only authorised individuals can access the records for privacy. Research can be done securely using smart contracts. Hospital receipts can be saved on the blockchain and automatically shared with insurance companies. The ledger can also manage supplies, supervise drugs, and ensure regulation compliance.
Electoral Polls
Smart contracts offer a secure environment, reducing the risk of manipulation in the voting system. Votes would be protected by a ledger, making them hard to decode. Smart contracts could also increase voter turnout. The current system is inefficient, requiring voters to wait in line, show ID, and complete forms. Online voting with smart contracts can attract more participants.
Music and Entertainment Industry
New artists depend on streaming revenues as they enter the industry. Smart contract apps can simplify royalty payments. These contracts can specify the royalty share for the record company and the artist. Instant payments benefit everyone involved.
Smart contracts could also solve the problem of royalty distribution in the OTT content world, where traditional agreements do not apply. This technology enables emerging artists and lesser-known actors to receive small, regular payments.
Real Estate
Hybrid contracts ensure compliance in real estate deals. The on-chain part executes the contract and initiates payments. The off-chain part stores the legal documents.
B2B Data Marketplaces
A data marketplace is a portal for buying and selling datasets or data streams from many sources. Smart contracts create fast-evolving markets that enable automated and secure transactions without human intervention.
Blockchain Platforms Supporting Smart Contracts
Many blockchain platforms support smart contracts. We highlight the most popular ones and discuss their features, benefits, and drawbacks.
1. Ethereum
Ethereum is a top platform for smart contracts, trusted by companies like Microsoft, JPMorgan Chase, and ConsenSys. The main programming languages are Solidity and Vyper. Smart contracts must be compiled into Bytecode for the Ethereum Virtual Machine (EVM) to execute them on the blockchain. Ethereum now uses a Proof-of-Work (PoW) consensus mechanism but is moving to Proof-of-Stake (PoS) with the Ethereum 2.0 upgrade.
2. Binance Smart Chain (BSC)
The Binance Smart Chain (BSC) was created by Binance, one of the largest cryptocurrency exchanges, and operates alongside other major cryptocurrencies like Bitcoin. This network offers low-cost, high-speed transactions facilitated by its underlying distributed ledger technology.
It is compatible with the Ethereum ecosystem and the Ethereum Virtual Machine (EVM), making project migration from the Ethereum blockchain to BSC easy. This blockchain uses a PoSA consensus mechanism, which combines Proof-of-Stake and Proof-of-Authority to balance decentralisation, security, and scalability.
3. Solana
The Solana blockchain network is fast and has low fees. It can handle thousands of transactions per second. Solana uses a unique consensus mechanism (Proof-of-History combined with Proof-of-Stake) for quick processing. This improves user experience and efficiency. The network’s ecosystem of dApps, DeFi platforms, and NFT marketplaces is growing rapidly.
4. Cardano (Plutus)
Cardano is a blockchain and smart contract platform using Proof-of-Stake. It is more energy-efficient than Proof-of-Work blockchains and supports high transaction throughput. The network prioritises security and privacy, requiring formal verification of smart contract code to ensure correctness and reduce attack points. Academic research and peer review drive Cardano’s development, lending it high credibility. The platform supports programming languages like Plutus and Marlowe.
5. Avalanche
The Avalanche network uses its unique, energy-efficient consensus mechanism. This system is secure and attack-resistant. The network is scalable and performs well. It supports creating subnetworks and custom blockchains.
6. Tezos
Tezos has a self-amending ledger that lets stakeholders vote on protocol upgrades, ensuring a democratic approach to blockchain development. It supports formal verification, which is crucial for smart contracts in high-stakes scenarios like financial services where security and correctness matter. Smart contracts on Tezos are written in Michelson and are designed for formal verification. Tezos uses a Liquid Proof-of-Stake (LPoS) consensus mechanism, which is more energy-efficient than traditional Proof of Work systems.
7. Polkadot
Polkadot lets different blockchains work together. Smart contracts on Polkadot interact with other blockchains. It uses Proof-of-Stake, which is more energy-efficient than Proof-of-Work. You can create custom blockchains, called Parachains, within the Polkadot network. Polkadot is great for building dApps that need cross-chain functionality and interoperability.
Challenges of Smart Contracts
Complexity
Smart contracts are complicated due to the involvement of multiple parties, complex algorithms, and different contractual protocols. The lack of standard practices in their creation leads to inconsistencies and potential vulnerabilities.
Coding Errors
Like any software, smart contracts can have coding errors. A tiny mistake can cause serious issues since contracts cannot be changed once they are on the blockchain.
Security Vulnerabilities
Smart contracts face security threats like reentrancy attacks, front-running, and overflow errors. Blockchain technology’s transparency allows malicious actors to find and exploit vulnerabilities.
Legal Uncertainties
Smart contracts operate in a legal and regulatory grey area. Without clear guidance and enforcement, disputes and contract failures may occur.
Smart Contracts vs Traditional Contracts
A major difference between smart contracts and traditional contracts is immutability. Smart contracts cannot be changed, while traditional contracts can. This immutability makes it harder for malicious actors to forge or tamper with smart contracts.
FAQs
Which are the Top smart contract languages?
Here are the top 6 smart contract programming languages, each with unique functionalities for different project needs:
- Solidity: The main language for writing smart contracts on the Ethereum Virtual Machine (EVM).
- Vyper: A language similar to Solidity but focusing on security and simplicity.
- Rust: Known for its performance and safety features.
- Clarity: Designed for clarity and predictability in smart contract execution.
- Move: Created by Facebook for the Libra blockchain, focused on flexibility and safety.
- Cairo: Used for writing smart contracts in the StarkNet ecosystem.
What are the smart contract’s terms?
Smart contracts are not legal agreements. They are transactions executed automatically by a computer program or protocol. They can automate payment obligations, such as transferring cryptocurrencies or other tokens.
Can a smart contract be a legally binding contract?
A smart contract can be a legally binding agreement, but this is not always the case. It must fullfill all legal requirements, such as the intent to form a contract, which can differ depending on the jurisdiction.
Do smart contracts run forever?
The code runs independently and indefinitely. Smart contract data can be updated and modified.
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