https://particl.wiki/learn/market/smsgParticl Secure Messaging (SMSG)
SecureMessaging, the DSN used to store data off-chain, is also used as the messaging protocol for the marketplace
SMSG 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. It operates parallel to Particl's network and is hosted on the same nodes running the blockchain.
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fparticl.wiki%2F_media%2Flearn%2Fmarket%2Fparticl-smsg-topology.png&t=665&c=4vXdMUXgNKaTOg)
All nodes continuously attempt to decrypt every incoming message, but can only succeed if the node is able to recalculate the HMAC hash accompanying the 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 are stripped from of any metadata, therefore it is impossible for anyone to extract information such as IP addresses, sender or receiver. The only metadata not stripped from SMSG messages are the hash, the encryption payload, and a temporary public key.
Cryptography
Reference format: The format for referencing data stored on the SMSG network is simple. The hash acts as the identifier and thus provides enough information for a node to retrieve the file and verify its integrity.
DSN ID SHA256 HASH (32 bytes)
0x01 85fc17f7069acd39a5c636cd0a6530651096128da447959f5e250824857dc559
Particl Open MarketplaceParticl's Open Marketplace is a decentralized marketplace built with privacy at its core. It offers a low-cost, secure and scalable e-commerce experience
Buy and sell products and services from anyone else in the world without leaving a trail and using your favorite cryptocurrency.
The Particl Open Marketplace is a hybrid between blockchain and peer-to-peer technologies. It operates with no central authority or middleman and is exclusively owned and operated by its network of participants. Its decentralized nature enables new opportunities that cannot be offered by any other marketplace.
The Open Marketplace focuses on four core values: privacy, security, scalability, and absolute decentralization. It attains this goal by leveraging a combination of many different protocols. Each of these protocols contribute to Particl's core values in their own way.
FeaturesThe Open Marketplace is private by default.This means it automatically keeps users' identities and data private without requiring any extra step from the user. The only exception to that rule is the Tor setup which isn't enabled by default for security measures.
The Particl team is committed to only use the best privacy protocols the industry offers. It also constantly research, develop, and maintain the solutions deployed in the marketplace. As absolute privacy and security is the modus operandi of the project, it supersedes anything else. This means there is no concession made that would weaken the privacy setup of the marketplace in favor of something else.
PaymentsAll payments and transactions made on the Open Marketplace are untraceable by default.
This is achieved by leveraging the Confidential Transactions (CT) and RingCT capabilities of the Particl coin (PART). These two protocols are integrated as the default types of payments, as specified by the OMP.
CT and RingCT transactions have been historically used on the Cryptonote codebase. Yet, the Particl team has adapted these protocols to be compatible with the Bitcoin codebase, which is the codebase used for the PART coin. The Bitcoin codebase gives more flexibility, security, and stability to the PART coin that the Cryptonote codebase would. A good example for this is the ability for the RingCT and CT protocols to interact with smart-contracts (i.e. the Open Marketplace). The coin also uses the Bulletproofs CT protocol improvement (currently on testnet) which reduces range proofs by about 70%. This ensures marketplace payments are both anonymous and scalable at the same time.
ListingsPublic listings on Particl's Open Marketplace are listings that are publicly available. Anyone can search for these listings using keywords and by navigating to the correct categories. Although these listings are public, they still offer a great level of privacy as all transactions are untraceable by default.
The only “identifiable” data public listings reveal is a unique and anonymous vendor ID. This ID cannot, however, link to any payment address or traceable identity.
No metadataThe Open Marketplace does not generate any sort of traceable data.
That much is true whether you are a buyer or a vendor. Metadata is “data about data” and can be very useful to track users. For example, pictures usually carry data such as the device used to take the picture, when it was taken, and even the precise geo-location of where the picture was taken. Any data stored off-chain on Particl's network is immediately stripped of all its metadata, making it impossible to trace people using metadata. This behavior is enabled by Particl's SMSG Data Storage Network.
IP address anonymizationIP addresses can easily be anonymized on the Open Marketplace by installing Tor and editing the configuration file of your Particl Desktop client. Doing so shields you from getting your real IP address to be broadcast to the network.
Particl Desktop currently doesn't automatically route connections through Tor for security measures. If that were the case, a new Particl Desktop version would need to be installed by the user every time Tor pushes a new update. Automatic Tor updates, on the other hand, introduce severe security vulnerabilities, especially in regards to the authenticity of the files being automatically pushed to the client.
The Particl team is aware of a few solutions to circumvent this issue. It is also looking into alternatives to Tor. Automatic IP address anonymization should make their way onto Particl Desktop in the future.
From:
https://particl.wiki/learn/market/start