NOTICE: It's an experiment and a very early draft! Please, feel free to submit your ideas or pull requests.

ZOLD is a crypto currency.

ZOLD is going to solve these problems:

  • Blockchain is slow and doesn't scale
  • Crypto mining makes strangers rich
  • High volatility makes cryptos suitable only for the black market

ZOLD is:

  • Fast
  • Scalable
  • Anonymous
  • As stable as USD

ZOLD principles include:

  • There is only one issuer: Zerocracy, Inc.
  • The only way to get ZOLD is to earn it (or to buy from someone)
  • Zerocracy guarantees to buy back for $1/ZOLD
  • No history of transactions
  • Consistency is guaranteed by protocols, not data
  • The entire code base is open source
  • The network of communicating nodes maintains wallets of users
  • At least 16 redundant copies of each wallet must exist
  • Each node has a trust level, as an integer (negatives mean no trust)
  • Each node earns 0.16% of each transaction it processes
  • Nodes lose trust when the information they provide can't be proven by other nodes
  • The list of 16 highly trusted "backbone" nodes is hardcoded in this Git repository
  • The wallet no.0 belongs to Zerocracy and may have a negative balance

How to Use

Install Rubygems and then run:

gem install zold

Then, either run it as a node:

zold run

Or do one of the following:

  • zold create creates a new wallet (you have to provide PGP keys)
  • zold pay sends a payment
  • zold check checks the balance of a wallet

For more options just run:

zold --help

Architecture

Each running node contains a list of wallets; each wallet contains:

  • ID: unsigned 64-bit integer
  • Public PGP key of the owner: 256 bytes (2048 bits)
  • Balance: signed 128-bit integer (in 10-12)
  • Version: unsigned 64-bit integer

The wallet with the largest version number contains the current balance.

There is a 3PC protocol to make payments:

  1. A node locks a place in a distributed payment queue.

  2. The node confirms the payment.

  3. Other nodes modify balances of sender's and recepient's wallets.

Phase I. Each node maintains a queue of payments, where each payment includes:

  • Payment ID: unsigned 32-bit integer unique for the node
  • Sender wallet ID and version
  • Recepient wallet ID and version
  • Processor wallet ID and version
  • Amount
  • PGP sign of the sender
  • List of friend IPs and their payment IDs in their queues

When a lock request arrives, the node asks its most trustable "friends" (other nodes) to lock a place in their queues and then compares their responses. If the three versions they managed to lock are not exactly the same, it asks them to try to lock again. The process repeats, until all friends' replies are similar.

To find the current balance of three wallets, each friend asks its friends around.

Phase II. The node sends a confirmation request to its friends, which includes their payment IDs.

Phase III. Each node modifies the balances in its local list of wallets and responds with a payment confirmation status. The payment gets removed from the queue.

Consistency and Security

The list of friends is hard-coded in the software. It includes only the nodes that are trusted by the creators of this software. The list may be extended in runtime, using the statistics of the most actively contributing nodes.

If, at Phase I, some node doesn't synchronize its responses with other nodes in more than eight attempts, it loses its trust level.

To avoid long-lasting locks of the queue, a payment is removed from the queue if it stays there for longer than 60 seconds.

Concerns

A DoS attack to the distribution payment queue is a potential threat.

Maybe it will be necessary to pay volunteers for the nodes they keep online 24x7.

License (MIT)

Copyright (c) 2018 Zerocracy, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.