Hacking
The unauthorized use or manipulation of computer systems or networks, often to exploit vulnerabilities, access data, or disrupt services.
Hal Finney
A pioneer in cryptography and early supporter of Bitcoin, known for receiving the first BTC transaction from Satoshi Nakamoto and contributing to its development.
Hard Cap
The fixed, maximum limit of tokens or funds a crypto project is allowed to raise, often set during an ICO or token launch.
Hard Fork (Blockchain)
A major protocol change that creates a new version of the blockchain, making previously valid blocks invalid and vice versa—often resulting in a chain split.
Hard Fork Combinator
A tool developed by IOHK for Cardano, allowing multiple protocol versions to be combined seamlessly after a hard fork without disrupting the blockchain.
Hard Peg
An exchange rate policy where a currency’s value is fixed to another currency, like a 1:1 ratio with the U.S. dollar.
Hardware Security Module (HSM)
A physical device used to manage and safeguard digital keys, often employed for secure cryptographic operations like encryption or signing.
Hardware Wallet
A physical device, often USB-like, that securely stores cryptocurrency private keys offline to protect against hacks and malware.
Hash
A unique fixed-length string of characters generated by a cryptographic function, used to verify and secure data on the blockchain.
Hash Function
A mathematical function that transforms any input into a fixed-size hash value—essential for data integrity and blockchain security.
Hash Power / Hash Rate
A measure of the total computational power being used to validate and secure transactions on a proof-of-work blockchain network.
Hashed Timelock Contract (HTLC)
A type of smart contract that enables trustless, time-bound transactions between two parties—commonly used in atomic swaps and Lightning Network.
Hashgraph Consensus Mechanism
An alternative to blockchain that uses a Directed Acyclic Graph (DAG) to reach consensus, offering faster and more scalable transaction processing.
Haskell Programming Language
A purely functional programming language known for its strong type security and immutability, used to build Cardano smart contracts.
Hedge Contract
A financial agreement designed to offset the risk of price volatility in an asset—used to lock in prices or reduce exposure to market fluctuations.
Hedge Fund
A pooled investment fund that uses advanced strategies across multiple asset classes to maximize returns, often taking both long and short positions.
Hidden Cap
An undisclosed funding limit set during a token sale to prevent large investors from dominating early contributions and skewing token distribution.
Hierarchical Deterministic Wallet (HD Wallet)
A type of wallet that generates multiple addresses from a single seed phrase, enhancing privacy and simplifying wallet backups.
Higher High
A bullish technical pattern where an asset’s new high closes above its previous high, indicating upward momentum.
Higher Low
A technical indicator where an asset’s new low is higher than the previous low—often a sign of an uptrend.
HODL
A misspelling of “hold” turned crypto meme, meaning to keep your assets long-term despite price volatility—often rephrased as “Hold On for Dear Life.”
Honeyminer
A crypto mining app that allows users to mine cryptocurrencies on their devices and earn small amounts of BTC or other coins passively.
Honeypot
A scam designed to lure users into investing in a fake crypto project or smart contract, only to trap their funds with no way to withdraw.
Hostage Byte Attack
A form of ransomware-style attack where malicious storage providers demand payment to release users' encrypted or withheld data.
Hosted Wallet
A wallet managed by a third-party service provider where the user does not control the private keys, often used for convenience or custodial setups.
Hot Storage
The online storage of crypto private keys for fast access and real-time trading—generally less secure than cold storage.
Hot Wallet
A crypto wallet connected to the internet, typically used for daily transactions and quick access but with increased security risk.
Howey Test
A legal test used in the U.S. to determine whether an asset qualifies as a security, based on four conditions defined by the SEC.
Human Keys
Cryptographic credentials generated based on personal identifiers—like biometric data, devices, or knowledge—to securely access Web3 tools and services.
Human-Readable Names
Names or addresses formatted in a way that’s easy for people to read and remember, like ENS domains, as opposed to complex blockchain addresses.
Huobi BTC (HBTC)
An ERC-20 token issued by Huobi that mirrors the price of Bitcoin 1:1, allowing BTC to be used within the Ethereum ecosystem.
Hybrid PoW/PoS
A blockchain consensus model combining Proof of Work and Proof of Stake to leverage the strengths of both security and energy efficiency.
Hydra (Cardano)
A layer-2 solution for Cardano that boosts scalability by enabling multiple parallel transaction channels—referred to as “Hydra heads.”
Hyperinflation
An extreme and rapid increase in prices, usually caused by loss of currency confidence, leading to reduced purchasing power and economic instability.
Hyperledger (Hyperledger Foundation)
An open-source blockchain initiative led by the Linux Foundation that supports enterprise-grade distributed ledger technologies.