Hush Terminology Learns You Good!

autoshielding

An optional feature that is enabled by default in some wallets where Hush wallets will automatically send funds to a zaddr from transparent addresses, on first use. This protects funds, giving them privacy, without users needing to understand why or do the operation themselves.

block

A collection of transactions, potentially zero, and a coinbase mining reward paid to miners. HUSH blocks have two coinbase per block, the second being the Hush Founders Reward (Dev Tax). HUSH blocks can be at most 4 megabytes in size, which is twice the size of Zcash and four times the size of a Bitcoin block.

checkpoint

A checkpoint is a consensus rule which says that a full node must have a certain block hash at a given height. It is a way to enforce that nodes sync a certain blockchain when other chainforks exist, either by accident or attack. It also can change how a full node validates certain blocks, since if a block has a lower height than a checkpoint block, we can see if it is an ancestor of the checkpoint block, and if it's not, we know it is invalid.

coinbase

The technical term for newly mined coins, which have no transaction history. They are different from UTXOs because they are not the output of a previous transaction.

consensus

Consensus code in a full node makes sure that all nodes will create the same exact data and hence the same transaction and block SHA256 hashes. When there is a bug in consensus code, it can cause a "chain fork", which often happens accidentally and also can be part of an attack.

Dev Tax

Hush Founders Reward is 10% of all coinbase mining rewards in all blocks go to the Hush Team, in perpetuity. These funds are used to run the project, including but not limited to:

• server fees
• domain fees
• dev bounties

In comparison, Zcash (ZEC) takes 20%, and has done since the genesis block. In HUSH, the dev tax was not added until after Block 500000 of the original network, which means that the Zcash Dev Tax is 20% of all supply, i.e. 4200000 ZEC. The HUSH Dev Tax is is less than 10% of circulating HUSH supply, because it was started much later.

DPoW

Delayed-Proof-of-Work, which protects HUSH with the hashrate security of Bitcoin. More info at https://dpow.hush.is

Founders Reward

See Dev Tax.

HIP

Hush Improvement Proposal hips

hushd

The main "full node" of hush. Downloads the full blockchain which is currently a few GB :)

https://git.hush.is/hush/hush3

HushChat

A new "chat GUI" encrypted messenger interface to Hush wallets.

ITM Attack

A shielded address linkability metadata leakage attack

Komodo (KMD)

The very first Zcash Protocol genesis block to be mined, before ZEC mainnet launched. Originally HUSH was a fork of ZEC source code (not a chain fork, we made our own genesis block), before we migrated to a fork of KMD source code in the current HUSH mainnet, where we also mined a new genesis block.

mainnet

The production network of a blockchain, as opposed to a testnet. It is similar to the master branch in Git.

Metaverse Metadata Attack

The concept of simulating the history of a blockchain to make it leak metadata via consensus oracle attack.

Sapling

The latest generation of shielded addresses (zaddrs) which are fast and have many provable guarantees about certain potential bugs existing.

Sapling Consolidation

An advanced feature originally developed by ZER which was ported to HUSH and improved in various ways, such as by adding Sietch support and reducing metadata leakage. It actively "consolidates" many ZUTXOs into single and hence more efficient-to-spend ZUTXOs, which makes wallets faster and also protects against dusting attacks.

Sprout

The original generation of shielded adddresses (zaddrs) which had many bugs, and were replaced with a new implementation that did not suffer from inflation attacks.

SDA

SilentDragonAndroid GUI mobile wallet

https://git.hush.is/hush/SilentDragonAndroid

SDL

SilentDragonLite GUI Wallet

https://git.hush.is/Hush/SilentDragonLite

SD

SilentDragon GUI Full Node Wallet

https://git.hush.is/hush/SilentDragon

Sietch

Privacy tech invented by Hush that protects against new attacks described on https://attackingzcash.com including the ITM attack in particular and Metaverse Metadata attacks in general.

More details: https://git.hush.is/hush/sietch

TADDR

Transparent address, which looks like R... on HUSH. Bitcoin only has taddrs, not zaddrs.

TXO

Transaction output, spent or unspent. Transactions may have many inputs and outputs.

UTXO

Unspent transaction output, from a transparent address. The balance of an address is the sum of the amounts of all UTXOs. If you have 75 cents in your pocket, made up of three 25 cent quarters, then you can think of a UTXO as the individual coins.

WITNESS

An internal data structure of shielded funds, which is stored inside wallet.dat file.

ZUTXO

Shielded unspent transaction output. If a zaddr receives 3 payments of 1 HUSH, it has 3 zutxos, each of 1 HUSH, for a total balance of 3 HUSH.

ZADDR

z address aka shielded adddress which looks like zs1.... on HUSH. A zaddr hides the sender and recipient addresses as well as the amount being sent, and hence give drastically more on-chain privacy than taddrs.

ZEC

Zcash mainnet

z2z

Enforcing that only zaddrs can be used as senders and receivers in a transaction.