Glossary

Account Accounts are a central part of the Ledgerium network and are an essential part of any transaction or contract. In Ledgerium, there are two types of accounts: Externally Owned accounts (EOA) and Contract accounts.

Address A Ledgerium address represents an account. For EOA, the address is derived as the last 20 bytes of the public key controlling the account, e.g., 74f68A6e428f060a1Dff3e9C89d22F2504416499. This is a hexadecimal format (base 16 notation), which is often indicated explicitly by appending 0x to the address. Web3.js and console functions accept addresses with or without this prefix but for transparency, we encourage their use. Since each byte of the address is represented by 2 hex characters, a prefixed address is 42 characters long. Several apps and APIs are also meant to implement the checksum-enabled address scheme.

ASIC The application-specific integrated circuit, in this case referring to an integrated circuit custom-built for cryptocurrency mining.

Attach The command used to initiate the Ledgerium Core Javascript console. geth attach

Balance The amount of cryptocurrency (in this case) belonging to an account.

Block A block is a package of data that contains zero or more transactions, the hash of the previous block ("parent"), and optionally other data. The total set of blocks, with every block except for the initial "genesis block" containing the hash of its parent, is called the blockchain and contains the entire transaction history of a network. Note that some blockchain-based cryptocurrencies use the word "ledger" instead of blockchain; the two are roughly equivalent, although in systems that use the term "ledger" each block generally contains a full copy of the current state (e.g. currency balances, partially fulfilled contracts, registrations) of every account allowing users to discard outdated historical data.

Blockchain An ever-extending series of data blocks that grows as new transactions are confirmed as part of a new block. Each new block is chained to the existing blockchain by a cryptographic proof-of-work.

Block Explorer A website that allows easy searching and extraction of data from the blockchain.

Block Header The data in a block which is unique to its content and the circumstances in which it was created. It includes the hash of the previous block's header, the version of the software the block is mined with, the timestamp and the Merkle root hash of the contents of the block.

Block Producer The peer node which participates for the consensus mechanism IBFT in the Ledgerium Blockchain. It is also called Validator node.

Block Propagation The process of transmitting a confirmed block to all other nodes in the network.

Block Validation The checking of the coherence of the cryptographic signature of the block with the history stored in the entire blockchain.

Blocktime The average time interval between the mining of two blocks.

Bootnode The node which can be used to initiate the discovery process when running a node. The endpoints of these nodes are recorded in the Ledgerium source code.

Chain Id A number which identifies a particular version of the Ledgerium network. It is also known with Network ID.

Checksum A count of the number of bits in a transmission that is included with the unit so that the receiving end can verify that the entirety of the message has been transmitted.

Crypto-fuel This is a loose term of 'gas', referring to the amount of cryptocurrency required to power a transaction.

Cryptoeconomics The economics of cryptocurrencies.

Coinbase Coinbase is the default name of the account on your node that acts as your primary account. If you do mining, mining rewards will be credited to this account. but is a more generic term for all cryptocurrency platforms.

Compiler A program that translates pieces of code written in high-level languages into low-level executable code.

Consensus The agreement among all nodes in the network about the state of the Ledgerium network.

Consortium Chain A blockchain where the consensus process is controlled by a pre-selected set of nodes. Ledgerium Blockchain is consortium chain.

Contract A persistent piece of code on the Ledgerium blockchain that encompasses a set of data and executable functions. These functions execute when Ledgerium transactions are made to them with certain input parameters. Based on the input parameters, the functions will execute and interact with data within and outside of the contract.

Daemon A computer program that runs as a background process instead of indirect control by an interactive user.

DAO (Decentralized Autonomous Organization) DAO is a type of contract on the blockchain application (or a suite of contracts) that is supposed to codify, enforce or automate the workings of an organization including governance, fund-raising, operations, spending and expansion.

DApp Stands for "decentralized application".

Decentralization The concept of moving the control and execution of computational processes away from a central entity.

Decentralized application (DApp) Service that operates without a central trusted party. An application that enables direct interaction/agreements/communication between end-users and/or resources without a middleman.

Deposit Digital property placed into a contract involving another party such that if certain conditions are not satisfied that property is automatically forfeited and either credited to a counterparty as insurance against the conditions or destroyed (= burnt = equally distributed) or donated to some charitable funds.

Digital Identity The set of cryptographically verifiable transactions signed by the same public key define the digital identity's behaviour. In many real-world scenarios (voting) it is desirable that digital identities coincide with real-world identities. Ensuring this without violence is an unsolved problem.

Digital Signature A mathematical scheme for demonstrating the authenticity of a digital message or documents.

Discovery (peer) The process of 'gossiping' with other nodes in the network to find out the state of other nodes on the network.

Encryption Encryption is the conversion of electronic data into a form unreadable by anyone except the owner of the correct decryption key.

Epoch Epoch is the interval between each regeneration of the DAG used as seed by the PoW algorithm Ethash. The epoch in specified as 30000 blocks.

Elliptic Curve (Cryptography) Refers to an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. See Elliptic Curve Cryptography.

EOA Externally Owned Account. An account controlled by a private key. If you own the private key associated with the EOA you have the ability to send XLG and messages from it. Contract accounts also have an address.

EVM Ethereum Virtual Machine, the decentralized computing platform which forms the core of the Ledgerium platform.

Exchange An online marketplace which facilitates the exchange of crypto or fiat currencies based on the market exchange rate.

Fast Sync Instead of processing the entire block-chain one link at a time, and replay all transactions that ever happened in history, fast syncing downloads the transaction receipts along the blocks and pulls an entire recent state database.

Faucet A website that dispenses (normally testnet e.g. Toorak, Flinders) XLG for free for users to test their DApps.

Gas Name for the cryptofuel that is consumed when code is executed by the EVM. The gas is paid for execution fee for every operation made on a Ledgerium blockchain.

Gas Limit The gas limit can apply to both individual transactions e.g. transaction gas limit and to blocks, block-gas-limit. For individual transactions, the gas limit represents the maximum amount of gas you indicate you are willing to pay for a contract execution transaction. It is meant to protect users from getting their XLG depleted when trying to execute buggy or malicious contracts. The block gas limit represents the maximum cumulative gas used for all the transactions in a block.

Gas Price Price in XLG of one unit of gas specified in a transaction. It remains in the range of 1 Babbage to 500 Shannon.

Gas Price Oracle A helper function of the Geth client that tries to find an appropriate default gas price when sending transactions.

GHOST Greedy Heaviest-Observed Sub-Tree is an alternative chain-selection method that is designed to incentivize stale blocks (uncles) as well, thus reducing the incentive for pool mining. In GHOST, even the confirmation given by stale blocks to previous blocks are considered valid, and the miners of the stale blocks are also rewarded with a mining reward.

Genesis Block The first block for the Ledgerium Blockchain.

Geth Ledgerium client adopted from Ethereum and Quorum implemented in the Golang programming language, based on the protocol as defined in the Ethereum Yellow Paper.

Hash A cryptographic function which takes an input (or 'message') and returns a fixed-size alphanumeric string, which is called the hash value (sometimes called a message digest, a digital fingerprint, a digest or a checksum). A hash function (or hash algorithm) is a process by which a document (i.e. a piece of data or file) is processed into a small piece of data (usually 32 bytes) which looks completely random, and from which no meaningful data can be recovered about the document, but which has the important property that the result of hashing one particular document is always the same. Additionally, it is crucially important that it is computationally infeasible to find two documents that have the same hash. Generally, changing even one letter in a document will completely randomize the hash; for example, the SHA3 hash of "Saturday" is c38bbc8e93c09f6ed3fe39b5135da91ad1a99d397ef16948606cdcbd14929f9d, whereas the SHA3 hash of "Caturday" is b4013c0eed56d5a0b448b02ec1d10dd18c1b3832068fbbdc65b98fa9b14b6dbf. Hashes are usually used as a way of creating a globally agreed-upon identifier for a particular document that cannot be forged.

Hashrate The number of hash calculations made per second.

Hexadecimal Common representation format for byte sequencing. Its advantage is that values are represented in a compact format using two characters per byte (the characters [0-9][a-f]).

IBFT Istanbul Byzantine Fault Tolerance is the consensus algorithm adopted by Ledgerium Blockchain, improves finality and increases throughput the network.

Identity A set of cryptographically verifiable interactions that have the property that they were all created by the same person.

IPC Interprocess communication (IPC) is a set of programming interfaces that allow a programmer to coordinate activities among different program processes that can run concurrently in an operating system.

JS Javascript.

Keyfile Every account's private key/address pair exists as a single keyfile. These are JSON text files which contains the encrypted private key of the account, which can only be decrypted with the password entered during account creation.

Log Event Contracts are triggered by transactions executed as part of the block verification. If conceived of as a function call, contract execution is asynchronous, and therefore they have no return value. Instead, contracts communicate to the outside world with log events. The log events are part of the transaction receipt which is produced when the transaction is executed. The receipts are stored in the receipt trie, the integrity of which is guaranteed by the fact that the current root of the receipt trie is part of the block header alongside the roots of state and state-trie. In a broad sense from the external perspective receipts are part of the Ledgerium system state except that they are not readable contracts internally.

Micropayment A micropayment is a financial transaction involving a very small sum of money (<1 USD) and usually one that occurs online.

Merkle Patricia Tree Merkle Patricia trees provide a cryptographically authenticated data structure that can be used to store all (key, value) bindings. They are fully deterministic, meaning that a Patricia tree with the same (key,value) bindings is guaranteed to be exactly the same down to the last byte and therefore have the same root hash, provide O(log(n)) efficiency for inserts, lookups and deletes, and are much easier to understand and code than more complex comparison-based alternatives like red-black trees.

Message A data transfer mechanism contracts use to communicate with other contracts. Messages can also be described as virtual objects that are never serialized and exist only in the Ledgerium execution environment.

Memory-hard Memory hard functions are processes that experience a drastic decrease in speed or feasibility when the amount of available memory even slightly decreases.

Mining The process of verifying transactions and contract execution on the Ledgerium blockchain in exchange for a reward in XLG with the mining of every block. It is the function of every Block Producer.

Mining Reward The number of cryptographic tokens (in this case XLG) that is given to the block producer who mined a new block.

NAT Network address translation (NAT) is a methodology of remapping one IP address space into another by modifying network address information in Internet Protocol (IP) datagram packet headers while they are in transit across a traffic routing device.

Network Hashrate The number of hash calculations the network can make per second collectively. This term is significant in classical Ethereum PoW/PoS Network, however, has less meaning on Ledgerium Blockchain.

Network ID A number which identifies a particular version of the Ledgerium network. It is also named as ChainID in some of the technical artifacts of Ledgerium Blockchain.

Nonce Number Used Once or Number Once. A nonce, in information technology, is a number generated for a specific use, such as session authentication. Typically, a nonce is some value that varies with time, although a very large random number is sometimes used. In general usage, nonce means “for the immediate occasion” or “for now.” In the case of Blockchain Proof of Work scenarios, the hash value, found by a Miner, matching the network's Difficulty thus proving the Block Validity is called Nonce as well.

Proof-of-work (PoW) It refers to a mathematical value that can act as the proof of having solved a resource and time consuming computational problem. This is the earliest production-ready consensus mechanism used by current Ethereum Mainnet.

Proof-of-Stake (PoS) An alternative method of mining blocks that require miners to demonstrate their possession of a certain amount of the currency of the network in question. This works on the principle that miners will be disincentivized to try to undermine a network in which they have a stake. PoS is less wasteful than PoW but is still often used to provide added security to the classical Ethereum Blockchain network.

Proof-of-Authority (PoA) An alternative method of mining blocks that require miners are pre-authorised and known to each other. PoA-based networks, transactions and blocks are validated by approved accounts, known as validators. PoA chains deliver comparatively fast transactions vis-a-vis PoW or PoS.

Private Chain A fully private blockchain is a blockchain where write permissions are kept centralized to one organization.

Peer Other computers on the network also running a Ledgerium node (Geth) with an exact copy of the blockchain that you have.

Peer to Peer Network A network of computers that are collectively able to perform functionalities normally only possible with centralized, server-based services.

Pending Transaction A transaction that is not yet confirmed by the Ledgerium network.

Presale Sale of cryptocurrency before the actual launch of the network.

Private Key A private key is a string of characters known only to the owner, that is paired with a public key to set off algorithms for text encryption and decryption.

Public Key A string of characters derived from a private key that can be made public. The public key can be used to verify the authenticity of any signature created using the private key.

Protocol A standard used to define a method of exchanging data over a computer network.

Port A network port is a communication endpoint used by one of the existing standards of establishing a network conversation (e.g. TCP, UDP).

Quorum Quorum is an Ethereum-based distributed ledger protocol backed up by JP Morgan that supports transaction and contract privacy.

RPC Remote Procedure Call, a protocol that a program uses to request a service from a program located in another computer in a network without having to understand the network details.

Serialization The process of converting a data structure into a sequence of bytes. Ledgerium internally uses an encoding format called recursive-length prefix encoding (RLP), described in the RLP section of the [wiki] (https://github.com/Ethereum/wiki/wiki/RLP).

Sharding The splitting of the space of possible accounts (contracts are accounts too) into subspaces, for example, based on the first digits of their numerical addresses. This allows for contract executions to be executed within 'shards' instead of network-wide, allowing for faster transactions and greater scalability.

Signing Producing a piece of data from the data to be signed using your private key, to prove that the data originates from you.

Sidechain A blockchain that branches off a main blockchain and checks in periodically with the main blockchain. Besides that, it runs independently from the main chain, and any security compromises in the sidechain will not affect the main chain. The Ledgerium Blockchain will support sidechains in future releases when it gets synched with forthcoming Etheruem 2.0.

State Refers to a snapshot of all balances and data at a particular point in time on the blockchain, normally referring to the condition at a particular block.

Static Node A feature supported by Geth, the Golang Ledgerium client, which makes it possible to always connect to specific peers. Static nodes are re-connected on disconnects. For details, see the :ref:section on static nodes <cr-static-nodes>.

Solidity Solidity is a high-level language whose syntax is similar to that of JavaScript and it is designed to compile to code for the Ledgerium Virtual Machine.

Syncing The process of downloading the entire blockchain.

selfdestruct A global variable in the Solidity language that allows you to destroy the current contract, sending its funds to the given address.

Testnet A mirror network of the production Ledgerium mainnet network that is meant for testing. Ledgerium has two testnet named Toorak and Flinders

Transaction The signed data package that stores a message to be sent from an externally owned account. Simply put, a transaction describes a transfer of information from an EOA to another EOA or a contract account.

Transaction Fee Also known as gas cost, it is the amount of XLG that the miners will charge for the execution of your transaction.

Trustless Refers to the ability of a network to trustworthily mediate transactions without any of the involved parties needing to trust anyone else.

Token System A fungible virtual good that can be traded. More formally, a token system is a database mapping addresses to numbers with the property that the primary allowed operation is a transfer of N tokens from A to B, with the conditions that N is non-negative, N is not greater than A's current balance, and a document authorizing the transfer is digitally signed by A. Secondary "issuance" and "consumption" operations may also exist, transaction fees may also be collected, and simultaneous multi-transfers with many parties may be possible. Typical use cases include currencies, cryptographic tokens inside of networks, company shares and digital gift cards.

Uncle Uncles are blockchain blocks found by a miner when a different miner has already found another block for the corresponding place in the blockchain. They are called “stale blocksâ€. The parent of an Uncle is an ancestor of the inserting block, located at the tip of the blockchain. In contrast to the Bitcoin network, Ledgerium rewards stale blocks as well in order to avoid to penalize miners with a bad connection to the network. This has no meaning in the Ledgerium Blockchain network because it has one block finality due to IBFT consensus mechanism.

Uncle Rate The number of uncles produced per block. This is not applicable on the Ledgerium Blockchain as explained in #Uncle

Unique Identity A set of cryptographically verifiable interactions that have the property that they were all created by the same person, with the added constraint that one person cannot have multiple unique identities.

Validator The peer node which participates for the consensus mechanism IBFT in the Ledgerium Blockchain. It is also called Block Producer node.

Virtual Machine In computing, it refers to an emulation of a particular computer system which runs the software. Ledgerium Blockchain uses Ethereum Virtual Machine to execute its executing code.

Wallet A wallet, in the most generic sense, refers to anything that can store XLG or any other crypto token. In the crypto space in general, the term wallet is used to mean anything from a single private/public key pair (like a single paper wallet) all the way to applications that manage multiple key pairs, like the Mist Ledgerium wallet.

Web3 The exact definition of the Web3 paradigm is still taking form, but it generally refers to the phenomenon of increased connectedness between all kinds of devices, decentralization of services and applications, semantic storage of information online and application of artificial intelligence to the web.

Web of trust The idea that if A highly rates B, and B highly rates C, then A is likely to trust C. Complicated and powerful mechanisms for determining the reliability of specific individuals in specific concepts can theoretically be gathered from this principle.

XLG XLG is the name of the currency used within Ledgerium. It is used to pay for computations within the EVM. Ambiguously, XLG is also the name of a unit in the system;