As the focus is to provide sender/receiver full privacy in one transaction, NIX team introduces the very first concept of 2 way privacy by implementing Pedersen Anonymous Deposit scheme called Commitment Key Packs, which enables full Zero-Knowledge proof transaction privacy between sender and receiver: 2 Way Ghosting mechanisn.
This never-done-before technology enables the ability to launch powerful private smart contracts on chain while allowing ZK-proof transaction edged privacy.
Although the technical procedure for achieving sender/receiver privacy in one transaction is complex in the backstage, it can be summarized as simple as sending coins from one Ghost Vault to another in the diagram below:
Every time NIX coins are ghosted, they go through the Ghost Protocol before entering the Ghost Vault, so they get destroyed and converted into Zerocoins; which, in turn, are stored into the vault. Once in there, NIX are no longer existent, instead, users own mixed-zerocoins that are impossible to trace.
Originally, before leaving the Ghost Vault, Zerocoins needed to be converted back to NIX through a process called un-ghosting.
If those re-created NIX coins leave the vault by being sent to a NIX address, they become public, and privacy is no-longer available as they can be traced throughout the blockchain.
To avoid that from happening, NIX Platform has created a Key list containing customized one-time-keys (Ghost Keys) which can be found in NIX core wallet. These receivers’ one-time-keys are used to unlock Zerocoins. The receiver must provide the sender with one Ghost Key.
Now, instead of unghosting NIX to a public address, the sender inputs receiver’s one-time key so that previously ghosted NIX get converted into new ghosted NIX and get deposited directly into receiver’s Ghost Vault without compromising any security. Once a Ghost Key gets used it gets burnt.
2 Way Ghosting feature offers full sender and receiver privacy in one transaction without the need of NIX addresses. This mechanism is so powerful that there is no way for user history to be compromised as address-less transactions are performed.
Commitment Key Packs technical paper here, demonstration video here.