Hash Function

A Hash or also called hash function is any algorithm that maps data of arbitrary length to data of a fixed length. The values returned by a hash function are called hash values, hash codes, hash sums, checksums or simply hashes. Recent development of internet payment networks and digital money, such as Bitcoin, also uses a form of 'hashing' for checksums, and has brought additional attention to the term.

Hash Power

The hash rate is the primary measure of a Bitcoin miner's performance. In 2014, a miner's performance was generally measured in Ghash/s, or billions of hashes per second.

Hot Wallet

A hot wallet refers to a Bitcoin wallet that is online and connected in some way to the Internet. It is a term that refers to bitcoins that are not being kept in cold storage. Bitcoin-related services and exchanges that are able to pay out withdrawals instantly can be said to be paying them from a "hot wallet". The term can also be used loosely to refer to keeping bitcoins in an exchange where they can be withdrawn on demand. Its real-world analogy is keeping cash on person: easy access, but greatest risk of unrecoverable theft in the event of an attack. Operating a "hot wallet" is also a risk to its owner, because most computer systems have hidden vulnerabilities of some sort that can eventually be used by hackers or malware to break into the system and steal the bitcoins. Keeping large amounts of bitcoins in a hot wallet is a fundamentally poor security practice. Most, if not all of the Bitcoin losses incurred in all the known hackings in Bitcoin history can be attributed to funds kept in hot wallets. Most reputable services offering Bitcoin withdrawal of some sort will keep a very limited number of bitcoins in a hot wallet to enable immediate withdrawals of small/typical amounts, but will require a delay and manual activity to process a larger withdrawal, as the bitcoins are retrieved from other storage.

Hardware Wallet

Hardware wallet is a physical electronic device, built for the sole purpose of securing bitcoins. The core innovation is that the hardware wallet must be connected to your computer, phone, or tablet before bitcoins may be spent. Hardware wallets are a good choice if you’re serious about security and convenient, reliable Bitcoin storage. Bitcoin hardware wallets keep private keys separate from vulnerable, internet-connected devices. Your all-important private keys are maintained in a secure offline environment on the hardware wallet, fully protected even should the device be plugged into a malware-infected computer. As bitcoins are digital, cybercriminals could, potentially, target your computer’s “software wallet” and steal them by accessing your private key. Generating and storing private keys offline using a hardware wallet ensures that hackers have no way to reach your bitcoins. Hackers would have to steal the hardware wallet itself, but even then, it can be protected with a PIN code. Don’t worry about your hardware wallet getting stolen, lost or damaged either; so long as you create a secret backup code, you can always retrieve your bitcoins.

Hard Fork

A hardfork is a change to the bitcoin protocol that makes previously invalid blocks/transactions valid, and therefore requires all users to upgrade. Any alteration to bitcoin which changes the block structure (including block hash), difficulty rules, or increases the set of valid transactions is a hardfork. However, some of these changes can be implemented by having the new transaction appear to older clients as a pay-to-anybody transaction (of a special form), and getting the miners to agree to reject blocks including the pay-to-anybody transaction unless the transaction validates under the new rules. This is known as a softfork.

Hash per Second

The hash rate is the measuring unit of the processing power of the Bitcoin network. The Bitcoin network must make intensive mathematical operations for security purposes. When the network reached a hash rate of 10 Th/s, it meant it could make 10 trillion calculations per second.

Hash

A Hash or also called hash function is any algorithm that maps data of arbitrary length to data of a fixed length. The values returned by a hash function are called hash values, hash codes, hash sums, checksums or simply hashes. Recent development of internet payment networks and digital money, such as Bitcoin, also uses a form of 'hashing' for checksums, and has brought additional attention to the term.

Hash Rate

The hash rate is the measuring unit of the processing power of the Bitcoin network. The Bitcoin network must make intensive mathematical operations for security purposes. When the network reached a hash rate of 10 Th/s, it meant it could make 10 trillion calculations per second.