Particl Platform

The Particl Platform allows anyone to use and build highly secure decentralized applications that possess industry-leading privacy and security parameters. The Particl team puts a heavy focus on usability and user experience. By making any Dapp that is built on Particl Platform as pretty and smooth as known market-leading products Particl gets a real shot at acquiring mainstream to non-crypto users. Any Dapp on the Particl Platform utilizes the PART Coin for processing transactions regardless of which currency payments will be made.

Particl Proof-of-Stake

The Particl platform uses a custom Proof-of-Stake protocol, Particl Proof-of-Stake (PPoS), as its consensus mechanism. Proof-of-Stake (PoS) is a type of algorithm by which a cryptocurrency blockchain network aims to achieve distributed consensus. In PoS-based cryptocurrencies, the creator of the next block is chosen via various combinations of random selection of wealth and age. In contrast, the algorithm of Proof-of-Work (PoW) based cryptocurrencies such as bitcoin rewards participants who solve complicated cryptographical puzzles in order to validate transactions and create new blocks (i.e. mining).

PPoS is built and improved upon the popular PoS3 protocol on top of which were added several security and utility features. Its scheduled inflation rate is 5% of its total supply during the first year, then decreasing by 1% every year until it plateaus at 2% indefinitely.

Cold Staking

Cold staking is enabled by smart-contract functionality and lets users securely delegate staking powers to “staking nodes” which contain no coin. The purpose of these “staking nodes” is to provide a dedicated resource connected to the Particl blockchain and stake on behalf of another wallet without being able to spend its coins. Cold staking nodes are intended to be used in combination with cold, hardware and paper wallets as well as multisig addresses, making it possible to stake “offline” coins with no risk of being hacked or exposing your public key to the network. Staking nodes can be set up on any device, secure or not, such as public/cloud servers, virtual machines or RPIs.

Cold Hardware Staking

It is currently possible to cold stake funds stored offline on a hardware wallet by setting up a Particl wallet on a Ledger hardware wallet. While cold staking does not store any password in memory and delegates staking powers to empty staking nodes, a cold wallet is still vulnerable when it's interacted with (i.e. when a transaction is executed) from an infected or untrusted computer. Hardware wallets fix this issue by not requiring any exchange of private key between the hardware wallet and the device/computer it is connected to, thus making hardware wallets safe even when they are interacted with from an infected computer.

Combining cold staking and hardware security effectively makes PPoS the most secure Proof-of-Stake protocol in the industry and fixes several issues generally associated with the Proof-of-Stake consensus protocol in general.

Quantum-Resistance & Privacy

Current Proof-of-Stake implementations have a vulnerability not present in Proof-of-Work whereby they reveal the public key of staking addresses when they find and sign blocks. The most dangerous attack by quantum computers is against public key cryptography. On traditional computers, it takes on the order of 2128 basic operations to get Bitcoin private keys associated with Bitcoin public keys. This number is so massively large that any attack using traditional computers is completely impractical. However, it is known for sure that it would take a sufficiently large quantum computer on the order of only 1283 basic quantum operations to be able to break a Bitcoin key using Shor’s algorithm. This might take some time, especially since the first quantum computers are likely to be extremely slow, but it is still very practical. It could be estimated that it is maybe 2 to 5 years until quantum computers become an issue, but any project that plans on staying relevant on a long period of time should tackle these vulnerabilities way before they become problematic.

It is worth mentioning that public keys are NOT public addresses. To reverse a private key from a public address, it would require more energy than what is available in the universe, therefore a quantum hacker cannot just go pick public addresses with large amounts and reverse those.

When a Particl block is staked from a cold staking node, the private key of the address on the staking node (which contains no coin) is broadcasted to the network instead of the private key of the address which contains the staking funds. Because cold staking nodes are able to sign staked blocks on behalf of any wallet, hot or cold, cold stakers can effectively remain anonymous and shielded from theoretical quantum computer attacks.

Passive Income

PPoS can serve as a great passive income tool. It rewards stakers a minmum rate of 5% per year for securing the network, then drops 1% every year until it plateaus at 2%. This staking reward rate is true if 100% of the total supply is put up for staking, but gets higher as less coins are being staked. For example, if 50% of the total network is being put up for staking, the staking reward rate for the first year would be of 10%.

The Particl platform also redirects any fee generated from it directly to stakers, including but not limited to currency transactions, marketplace listing fees, extended messaging, privacy balance transfers and others, meaning staking becomes more profitable as the platform gets more traffic.

Decentralized Voting

Integrated into PPoS is a blockchain voting system that can be used by any Particl user to poll others or vote. This tool allows the platform’s community to provably reach consensus and better coordinate itself. Polls run for a desired number of blocks and each staked block is a voting ticket, meaning the more blocks a staker finds, the more of his votes are registered. A staker can vote for any number of polls and they will all receive one vote for the selected option once the staker finds a block.

Embedding voting into PPoS means people who do not have any stake in the platform can’t vote, leaving the decisional power entirely up to the community of users.

Particl Foundation Self-Funding

The Particl Foundation, the Swiss legal foundation which supports the Particl project, gets 10% of all the staking rewards on the Particl network. This serves as a self-funding mechanism for the Particl Foundation to financially support, promote and market the Particl platform. This mechanism ensures the self-sustainability of the project and becomes more profitable as the speculative price of the Particl coin increases.

To get more details about Particl Proof-of-Stake, visit its dedicated page here.

Data Storage Networks (DSN)

Data Storage Networks (DSN) are used on Particl to store any data (i.e. marketplace-related data such as images) off-chain. This allows the platform to scale well regardless of the amount of data it uses.

DSN is a generic term that describes a specific set of software with the purpose of storing and retrieving data on the internet. The usage of the term DSN is simply a layer of abstraction as it is not required to know how a specific DSN works internally as long as it can store blobs of data and later retrieve them using a comparable cryptographic identifier. Popular DSN include BitMessage, IPFS, SMSG, HTTPs, TOR, and etc.

A small hash of the hosted content is created and stored on the Particl blockchain when it is used to store data on a DSN. To verify the integrity of data when it is retrieved back from the DSN, its hash is recomputed and compared with the one stored on the Particl blockchain. The data is considered trusted if the hashes match, and rejected by the platform if they don’t.

Extensibility & Protocol-Agnosticism

Technology moves at an exponential rate, and the very few protocols that survive the test of time are all designed with extensibility in mind. A protocol looking to be relevant on a long enough timeline should be both robust and flexible enough that it easily allows any developer to securely expand it. The development of data storage networks (DHTs, BitTorrent, IPFS) and blockchain solutions is still young, there aren't any clear “winners” that meet all criteria nor may there ever be, thus the protocol must accommodate for it.

Particl’s way to deal with this reality is with the protocol agnosticism built at its core. The platform is indeed designed to be able to interact and exchange data with any DSN rather than using the same hard-coded DSN everytime regardless of context or user preference.

SMSG

SecureMessaging (SMSG), Particl’s very own DSN, is a decentralized P2P message mixnet where all nodes store a copy of everyone's end-to-end encrypted messages and data for a duration of 48 hours (which can be increased for a fee). It is the default and most private DSN available for use on the platform. The reference implementation is developed in C++ and incorporated into the Particl daemon, allowing it to operate over the same peer to peer network as the Particl blockchain.

All nodes continuously attempt to decrypt every incoming message, but can only succeed if the node is able to recalculate the HMAC hash accompanying said message. If the hash check fails, then it can not be decrypted by the node, which means the message was either fraudulent, tampered with or meant for another node. SMSG messages and data are stripped from almost any metadata, therefore it is impossible for anyone to extract information such as IP addresses, sender or receiver. The only metadata accompanying data on SMSG are the hash, the encryption payload and a temporary public key.

IP Anonymization

Just like any cryptocurrency which builds on the Bitcoin codebase, the Particl platform allows its users to easily route their connection through the Tor network in order to hide their true IP address from the rest of the network. Tor is a decentralized node network for enabling anonymous communication. It directs Internet traffic through a free, worldwide and volunteer overlay network consisting of more than seven thousand relays to conceal users' location and usage from anyone conducting network surveillance or traffic analysis. Using Tor makes it much more difficult for a third-party to trace a user’s real IP address across the Particl network.

Onion routing is implemented by encryption in the application layer of a communication protocol stack, nested like the layers of an onion. Tor encrypts the data, including the next node destination IP address, multiple times and sends it through a virtual circuit comprising successive, random-selection Tor relays. Each relay decrypts a layer of encryption to reveal the next relay in the circuit to pass the remaining encrypted data on to it. The final relay decrypts the innermost layer of encryption and sends the original data to its destination without revealing or knowing the source IP address. Because the routing of the communication is partly concealed at every hop in the Tor circuit, this method eliminates any single point at which the communicating peers can be determined through network surveillance that relies upon knowing its source and destination.

Currency Agnosticism

A decentralized privacy platform focused on free markets cannot be limited by its own built-in token system, especially now that there are so many coins out there. Our goal is to lower barriers of entry and reduce friction in online shopping, allowing for easier adoption by buyers and vendors anywhere in the world.

In the spirit of connecting many different crypto communities together, the Particl platform is designed in such a way that it can accept almost any currency using two different methods. However, as the platform (marketplace, extended messaging, future Dapps, etc) requires PART to function in a private way (CT and RingCT), all incoming currency transactions are automatically converted into PART.

Atomic Swaps

Atomic swaps are decentralized and trustless trade between two users of different cryptocurrencies. As the blockchains are not related and transactions cannot be reversed, this provides no protection against one of the party never honoring their end of the trade. One common solution to this problem is to introduce a mutually-trusted third party for escrow, however this represents a scalability and privacy problem. It also does not offer any protection against collusion. Atomic swaps solve this problem without the need for a third party by using timed smart-contracts on both chains.

Atomic swaps involve each party paying into a contract transaction, one contract for each blockchain. The contracts contain an output that is spendable by either party, but the rules required for redemption are different for each party involved.

One party (called counterparty 1 or the initiator) generates a secret key and sends the intended trade amount into a smart-contract. The second party (called counterparty2 or the participant) can only redeem the funds by knowing the secret key. If a pre-determined period of time (typically 48 hours) expires after the smart-contract transaction has been mined or staked and the funds have not been redeemed by the participant, the funds can be refunded back to the initiator's wallet. For simplicity, we assume the initiator wishes to trade Particl for Decred with the participant. The initiator can also trade Decred for Particl and the steps will be the same, but with each step performed on the other blockchain. At this point, the participant is unable to claim the funds from the initiator's Particl smart-contract because the secret key is unknown by them. If the initiator revealed their secret key at this moment, the participant could claim the funds from the contract without ever honoring their end of the trade, leaving the initiator at a loss.

To avoid this, the participant creates a similar smart-contract but on the Decred blockchain and sends the intended Decred amount into it. However, for the initiator to redeem the output, their own secret key must be revealed to the participant. For the participant to create their smart-contract, the initiator must reveal not the secret key (since the participant could stil claim funds and not honor their end of the deal), but a cryptographic hash of the secret key to the participant so that the smart-contract can be properly deployed. The participant's contract can equally be refunded after a pre-determined period of time.

The initiator then redeems the participant's Decred funds by revealing the secret key to the participant’s smart-contract. The secret key is then extracted from the initiator's redeeming Decred transaction providing the participant with the ability to redeem the initiator's Particl contract.

This procedure is atomic (with timeout) as it gives each party a set period of time to redeem their coins on the other blockchain before a refund can be performed. This is the best option for people requiring privacy, and is also probably going to be the cheapest to use.

Third-Party Integrations

Using the very flexible and modular Particl Wallet, third-parties can easily be integrated to enhance the user experience and provide services. One such example is the integration of account-less exchanges such as Changelly, Shapeshift, or Altcoin.io. As these accounts do not require any account or KYC/AML verifications, they can easily be integrated directly into the Particl Wallet.

While not as private and cheap than atomic swaps, third-party services do offer some advantages over their decentralized counterpart. Liquidity and volume, for one, can be much better on centralized exchanges with more users. Some of these services (such as Changelly) also offer fiat options and pairs which allow the Particl Wallet to offer in-wallet fiat trading. The data fetched from these services’ APIs can also be used to facilitate many future wallet functions such as displaying fiat balances, setting listings in fiat prices, offering credit card deposits, etc.

Privacy Smart-Contracts

While not turing-complete, Particl is still able to deploy secure and complex smart-contracts. Good examples include the entire Particl marketplace, the MAD escrow mechanism and cold staking. Any developer can deploy their own Dapp on Particl and use the CT and RingCT privacy protocols to make contracts that natively respect users’ rights to privacy.