The Key “H” Concepts Everyone Must Understand in the Crypto Space

4 min readAug 25, 2022


If you have been following our series on the different DeFi concepts, you will discover that we have covered letters ‘A to G’. Now, we want to look at the most relevant concepts that begin with the letter ‘H’. Read and enjoy!


Hack or Hacking is an illegal act of breaking into a network or computer system by third-party cybercriminals. They execute this with malicious intentions like stealing sensitive data or funds. The process of Hack can be done legitimately to stop cybercriminals from executing their online criminal activities. These legitimate actions could come from an enterprise, government, or private entities.


Hackathon is an event where software engineers compete to design software programs, working applications, or an entire computer network. It is a time-sensitive event held by a consortium, firm, or related entity like blockchain industries or FinTech. The event presents several price categories for winners with a specific focus on the programming languages used, type of operating system, or the demography of programmers involved.


Halving is a term used when the reward for mining new blocks reduces by 50% (Half). This event happens to miners at fixed intervals. Bitcoin’s block reward, for instance, is halved once every four years at every 210,000 blocks.

Hardware Wallet

A hardware wallet usually refers to an offline or cold wallet. It is a non-custodial wallet that looks like a USB stick. They are technically connected to the internet atimes via USB or Bluetooth. Hardware wallet transactions are signed ‘in-device’, this implies that transactions have been signed offline before broadcasting to the blockchain using the internet. This security feature made them the most secure storage device and malware cannot sign its transactions or access the keys.

Hash Function and Hash Rate

Hash functions are irreversible one-way function algorithms that do not reveal the original hash data. It converts various sizes of data into a fixed-length hexadecimal hash or number. During the transaction validation process, the Bitcoin blockchain uses the SHA-256 hash algorithm.

However, the hash rate is a unit for measuring the computing power of a Proof-of-Work (PoW) consensus mechanism in tera-hashes per second (TH/s). The rate of increase or decrease depends on the number of miners that operate on the network.

HMAC-Based One-Time Password (HOTP)

This is a password system that uses a one-time password algorithm for security just like two-factor authentication (2FA). HOTP uses a Hash-Based Message Authentication Code (HMAC) and is similar to Time-based One-Time Passwords (TOTPs). The HOTP mechanism allows only the user with access to the OTP to log in to different web pages using the authentication application with their mobile phones.

HODL (Hold)

It is a term used to mean buying and keeping crypto assets instead of selling them. ‘Hold’ is a slang term often used during bear markets to discourage investors from selling off or liquidating their assets. It originates from a post on Bitcoin talk where a poster spelled ‘hold’ incorrectly. The word later became a crypto term and a meme.

Hot (Online) Wallet

This is a type of crypto wallet connected directly to the internet. Unlike cold wallets, the assets in this wallet are held online. A hot wallet is not as secure as a hardware wallet.

Huobi (Cryptocurrency Exchange)

Huobi is among the popular crypto exchanges that provide services for institutional and retail investors. It was founded by the CEO Leon Li in 2013 and has a blockchain known as Huobi Eco Chain. Huobi has a bitcoin version called Huobi BTC (hBTC).

Hybrid Blockchain

A hybrid blockchain comprises a combination of the public and private blockchain elements. The network architecture often includes a main public chain and private side chains of different uses linked back to the main chain and public access.


An open-source blockchain project that became useful in December 2015 through the Linux Foundation. The mission of the project is to improve multi-industry collaboration for blockchain technology. The target is to increase the reliability and performance of Distributed ledger technology (DTL) to support business transactions globally. To this end, Hyperledger has received contributions from JP Morgan, IBM, and other large-scale global enterprises. The blockchain project is made of four main protocols including Hyperledger Besu, Hyperledger Sawtooth, Hyperledger Fabric, and Hyperledger Iroha.

Hypertext Transfer Protocol (HTTP)

HTTP is a foundational layer of the internet that allows communication between web pages, hypertext, hyperlinks, data, etc with various types of web servers that displays information to users through a screen or user interface (UI). HTTP allows hypermedia data such as HTML to operate online and also interacts with various web-based systems. They include Internet Protocol (IP), JavaScript, application programming interfaces (APIs), cascading style sheets (CSSs), and the Transmission Control Protocol (TCP).

Closing Remarks

Wow! DeFi terms are really vast. It only requires patience and consistency to become a professional in the space. However, the repeated efforts of mastering the concepts under each alphabet will eventually push one from a newbie status to a legendary status in a few months.

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