XRP

The Ripple project was developed from 2004 to 2012. This network is not based on blockchain, but on a custom developed decentralized ledger. The code of Ripple cryptocurrency is written in C++. All 100 billion XRP coins were created at the same time when the project was launched. XRP coins can be stored in PC wallets, mobile and hardware wallets. The advantages of Ripple are high transaction speed and low commissions, the main disadvantage of Ripple is high network centralization.

Ripple relies on the RPCA (Ripple Protocol consensus algorithm) to validate transactions. This means that a Ripple node can be in one of three states: follower, candidate, and leader. All XRP nodes start with the follower state. There is no leader public node in the network yet, and public node candidates poll each other. The candidate gets the leader status, if the majority of candidate votes have been cast for the leader to have the most complete version of the transactions database. All further changes in the states of XRP nodes are synchronized with the leader. The appearance of a transaction in the network changes the state of one of the Ripple nodes. Next, the state of follower free public nodes is transferred, and the leader nodes provider waits until most follower XRP nodes change their state. The final step is for the leader Ripple node to update its state by looking at the state of the followers. These operations are repeated with each new transaction.

The Ripple cryptocurrency network is a distributed system of peer-to-peer XRP nodes. Every few seconds free blockchain nodes poll each other's state, figuring out which of them has the most complete transactions database at the moment and synchronizing their states. Any transaction between free blockchain nodes changes the state of the transactions database. The greater the number of Ripple nodes, the harder it is for an attacker to gain control of the network as a whole. Ripple maintains a list of identified trusted participants who are authorized to validate transactions. This system allows the Ripple network to run faster than most cryptocurrencies, but at the expense of decentralization.

On top of the Ripple nodes network is built the RippleNet network for payments and exchange of various assets. RippleNet consists of components such as xRapid, xCurrent and xVia. The Xrapid system relies on the Ripple decentralized ledger to make exchanges directly between different fiat currencies. To do this, a bridge is created between two Ripple nodes in different countries. The Ripple network also supports the Interledger protocol for connecting different payment networks and blockchains. Interledger is the basis for the xCurrent network, which connects financial institutions in different countries. xCurrent includes an encrypted messenger for exchange rates and other important financial information, and a validator nodes provider for instant confirmation of transactions. The Interledger protocol has compatibility with banking solutions already in use. Ripple also uses a standard API for checking accounts and other payment information called xVia.

The Ripple cryptocurrency network has options for both creating smart contracts and issuing custom tokens. Ripple smart contracts are able to use oracles to obtain and further exploit data. A separate company, Codius, is now developing smart contracts for Ripple. The digital assets issued on the Ripple network are called IOUs. The exchange between them is possible on the decentralized trading platform XRP Ledger.