**In this article we focus on the difference between storage, memory, and stack in Ethereum. We will also give a Solidity code sample and calculation examples.**

# Author: Mario

This calculator converts the bit value into the target.

An extensive explanation of the Bitcoin difficulty and how target, difficulty and bits are related can be found in this article: Bitcoin difficulty and Target

## Bitcoin Mining Difficulty & Target

**Definition**: The Bitcoin mining difficulty defines how hard it is to mine a new block. In average it takes ten minutes to mine a block.

A general explanation of the mining difficulty can be found here: There are two values we need to consider:

## Mining Difficulty Blockchain

## Block Reward – Blockchain

## Block Reward Definition

The block reward in a blockchain is the payment a miner or block creator receives, if he finds a valid block (see mining). In Proof of Work systems it is also called mining reward.

The block reward serves as a remuneration of the miner or block creator for its work. It is therefore part of the incentive structure to keep the network safe.

## Blockchain & Bitcoin Mining

**Explanation**: Bitcoin Mining is the process of creating new coins while validating transactions and creating blocks. This is usually done by a proof of work (PoW) algorithm. But there are also other algorithms like proof of stake (PoS), delegated proof of Stake, proof of capacity (PoC), proof of elapsed time (PoET), etc.

**Definition:** The Bitcoin proof of work is the underlying consensus algorithm for the bitcoin blockchain network. It aims to find a combination of predefined inputs which result in a hash value lower than a certain target threshold.

**Definition**: A hash function is a function which takes a value of arbitrary length as input (preimage) and calculates an output (digest) of fixed length.

In this post we explain what hash functions are and how they work.

This post provides a collection of material dealing with the history and technical development of Ethereum.

**VRN = Verifiable Random Number**

A VRN is a function that creates a random number in decentralized fashion. The Outcome of this function can be verified by thirdparties. This is important to confirmt that the resulting number is truely (pseudo)random.

## Properties of VRN

Desired properties of a VRNs are:

- Availability/ Livelines
- Quantum Resistence
- Verifiability
- Unbiased
- Unpredictability
- Scaleability

## Material / Ressources for Verifiable Random Functions (VRN)

### Overview Ressources

XOR, Commit Verify, RANDAO, Hash Onions, Pedersens Scheme

- Explains a solution to the last actor problem by using a threshold scheme from 6:15
- BLS Threshold Signatures