📔Glossary

Welcome to our Glossary, a curated collection of key terms and definitions designed to help you navigate our documentation with ease and get the most out of your Flashback experience.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

B

Block: A blockchain unit containing time-stamped information such as transactions or contract states.

Blockchain: A method of storing and transmitting data through linked blocks protected against modification.

Blockchain Layer: An abstract layer related to the validator's consensus and operations such as the EVM compatibility or the capacity to launch Layer-2 solutions.

C

Casper Friendly Finality Gadget (Casper-FFG): The protocol with which Ethereum gives finality to transactions on-chain and serves as the basis for the Proof of Stake protocol.

Cold Data Storage: Storing data that isn't frequently accessed or used. You're keeping them for safekeeping, but you don't need to access them often. This is different from "hot" data storage, which is for information that needs to be quickly and frequently accessed⁠. For example, old business records that need to be kept for compliance but aren't used day-to-day would be cold storage.

Content Service Layer: An abstract layer that gathers all the service gateways and the content-related protocols developed and proposed by service gateways. This means there are no common standards, and every service gateway can execute its protocols.

D

DePin: "Decentralized Physical Infrastructure Networks" are a way to create networks where physical infrastructure (in Flashback's case, storage infrastructure) is distributed across many different locations and providers instead of being controlled by one central company⁠.

E

Ethereum Virtual Machine (EVM): The abstracted execution layer for transactions and smart contracts. It allows the deployment of everything running on the Ethereum protocol.

F

File storage (FS) contract: A contract submitted between a user and the network that specifies the storage duration of a file, the storage nodes hosting the file, the cumulative operating fees, and other elements necessary for the proper functioning of the storage of the user's file.

G

Gas Fees: Gas fees are individuals' payments to complete a blockchain transaction or execute a smart contract.

Gasper: It is the combination of Casper-FFG and LMD-GHOST. It defines the finality rules and fork selection rules for the stability and security of the blockchain and the layer-1 blockchain infrastructure.

H

Hot data storage: The fast access and delivery of frequently used or actively processed data. Unlike cold storage (archived data), hot data requires immediate availability and quick response times for applications like gaming and AI training⁠. Hot data accounts for 99% of the serviceable addressable data storage market.

I

J

K

L

Latest Message-driven Greedy Heaviest Observed SubTree (LMD-GHOST): The fork-choice algorithm used to determine the “longest” chain with PoS consensus.

Layer-1: It gathers all the validators, protocols, full nodes, and other technical features that are essential components of the security, decnetralization, and scalability of the Nephele protocol.

M

N

O

Operating Fees: These fees correspond to a payment made to the storage provider. The storage provider is responsible for stating the operating fees in the storage node contract to support their maintenance costs, hardware and software, and other related costs to the storage.

P

Proof of Authority (PoA): A limited number of pre-approved validators create new blocks based on their reputation.

Proof of Capacity (PoC): Miners allocate disk space for mining, increasing their chances of adding new blocks based on the amount of space allocated.

Proof-of-Replication (PoRep): PoRep is a proof system that a server can use to demonstrate to a network publicly that it is dedicating unique resources to storing one or more replicas of a data file.

Proof-of-SpaceTime (PoSt): A cryptographic protocol used primarily to verify the integrity of a remote file. It is done by sending an encoded copy of the data to a server and executing a challenge-response protocol to check the data's integrity. This protocol is robust when considering the efficiency of a cloud storage server.

Proof-of-Stake (PoS): An alternative algorithm for achieving consensus on a distributed peer-to-peer network used in blockchain systems to verify transactions and add new blocks. Unlike proof-of-work, proof-of-stake requires little computing power but rather a specified amount of cryptocurrency that serves as the "stake" to participate in creating and adding blocks.

Proof of Work (PoW): A consensus mechanism where miners solve cryptographic puzzles to add new blocks to the blockchain by using th principle of hashrate computed by dedicated machines.

Q

Quality-of-Network (QoN) Optimizer: PoSt challenge-based economic incentive algorithm that selects the best performing node for a specific file and pays out a part of the file storage contract fees to it.

R

S

Service Gateway: The service responsible for serving files to and from the network. Represented by the public key which sign, and executes the negotiation or execution of a contracts the contract on-chain, it can abstract the underlying signing and challenge creation from the end user, in exchange for a monetary incentive paid out at the contract end. It can be substituted by a technical user, who interacts natively with the contracts.

Service Level Agreements: Formal contracts between a service provider and a customer that define the specific performance standards, availability, and quality metrics the provider must meet. They serve as a framework for accountability, outlining remedies, penalties, or compensations if agreed-upon service levels are not achieved.

Single points of failure: A component in a system where, if it fails, the entire system stops working.

Smart Contract: It is a computer program that facilitates, verifies and executes the negotiation or execution of a contract, or renders a contractual clause useless. This computer program has a specific size, and every execution in the blockchain uses gas fees.

Smart Contract Fees: These fees correspond to the costs of storing a file in the network. In the network, the standard data fees are equal to 100 gwei. It is independent of the time and size of the file on the network.

Slashing: The act of reducing a validator's stake in the case of a breach of consensus.

Storage and Staking Node (SSN) [deprecated naming]: A node (peer) that stores and delivers network users' data and performs the PoS, PoSt and PoRep consensus algorithms. This node requires a "stake" submission and other storage-related information in an SSN contract.

Storage Layer: An abstract layer of the incentive algorithms for the validators and service gateways, committed proofs, and all the related operations related to the decentralized storage of the network.

Storage Provider: An entity (individual or business) that owns one or multiple validators in the network where every validator has an active contribution to the storage layer while automatically contributing to the blockchain layer.

T

Token emission: The tokens generated by the blockchain from the genesis.

U

V

Validator: A node (peer) in the network that verifies blocks. It participates in the blockchain consensus, which is essential for a healthy decentralized network.

Validator Contract: A contract that specifies the "stake", the participation to the storage layer, the operating fee of the node, and other storage information.

W

Web: The Web is a system for managing and transferring information. There are three generations:

• The Web1: (1989) It represents the globalization of information transfer in digital form, whereas it was mainly analog or physical. This was the beginning of the Internet.

• The Web2: (1997) The advent of the "social" web. It's the ability for individuals to interact through the web to perform everyday actions. The "social" web is often represented by exchange communities called "social networks", which are managed by giant centralized entities like Google or Amazon. Telecommuting and online shopping are also part of this social evolution.

• The Web3: (2008) It all started with the Bitcoin project. In the wake of the financial crisis, individuals decided to transfer social trust (held by banks) to a blockchain-based network. This marked the beginning of the development of decentralized governance architectures/networks, i.e. offering individuals the freedom to be in full control of their assets and communication data through digital (algorithmic) means rather than human trust.

X

Y

Z

Zero-Knowledge Proofs (ZKPs): Allows one party to prove to another that they know a value without revealing any additional information.