Invariant
A property that should remain true across all valid states or executions of a smart contract or protocol.
Explain Like I'm 12
A property that should remain true across all valid states or executions of a smart contract or protocol.
Why It Matters
Security concepts help users and developers recognize common blockchain attack surfaces and defenses.
Knowledge Explorer
Explore This Concept in the Knowledge Graph
See how Invariant connects to other concepts, books, research, and developer resources.
Related Terms
Phishing
Phishing is a social engineering attack where malicious actors impersonate legitimate platforms, services, or individuals to deceive users into disclosing sensitive information, such as private keys, seed phrases, or login credentials. In the crypto sector, phishing is highly sophisticated; attackers often create fake websites, send fraudulent emails, or use social media bots to trick users into signing malicious transactions that drain their wallets.
Private Key
A private key is a secret, mathematically generated string of characters that grants the owner complete control over an associated cryptocurrency address. It acts as a digital signature tool, allowing users to authorize transactions and prove ownership of funds. In a decentralized network, the private key is the ultimate proof of authority; whoever possesses the private key effectively owns the assets associated with the corresponding address. It is never meant to be shared with anyone.
Smart Contract Audit
A structured review of smart-contract code and system design intended to identify vulnerabilities, logic errors, and security risks.
Sybil Attack
A Sybil attack is a security threat in decentralized networks where an attacker creates a large number of pseudonymous identities to gain a disproportionate influence over the system. By controlling the majority of nodes or participating addresses, the attacker can disrupt network consensus, censor transactions, or manipulate voting processes in governance mechanisms, thereby subverting the decentralization and integrity of the blockchain.
51% Attack
An attack where one entity or coalition controls enough consensus power to reorganize blocks, censor transactions, or attempt double spending.
Address Poisoning
A scam where attackers create lookalike address activity so victims may accidentally send funds to the wrong address.
Related Articles
Building Secure Smart Contracts: Best Practices for Web3 Developers:
Smart contracts are the backbone of the decentralized web, enabling everything from decentralized finance (DeFi) to NFTs, DAOs, and beyond. These self-executing agreements, written in code and stored on the blockchain, operate autonomously, executing transactions and enforcing rules without human in
2025 Security Lessons: Hacks, Exploits & the Push for Better Audits
Why the failures of 2025 will shape Web3’s security standards for the next decade. If 2025 taught the crypto industry anything, it’s this: Security is no longer optional — it’s existential. Despite enormous technical progress, 2025 saw a wave of high-profile hacks, insider exploits, governance attac