Satoshi

The smallest unit in Bitcoin named after Satoshi Nakamoto, the creator of Bitcoin and blockchain. It equals 0.00000001 BTC.

Satoshi Nakamoto

The pseudonym of the person/people who created Bitcoin, whose real name/names are not known.

Scalability

A change in size or scale in order to handle a network’s demands. Used to refer to a blockchain project’s ability to handle network traffic, future growth, and capacity in its intended application.

Script Witness

It contains signatures and public keys, which can together unlock bitcoins from SegWit transactions. Each SegWIt input contains its own Script Witness. Not to be confused with Witness Script.

ScriptPubKey

Represents a script which controls how bitcoins can be spent. It locks the bitcoin until it can be unlocked by providing an answer, depending on the type of the transaction.

ScriptSig

Represents a specific input script that unlocks funds from the specific crypto transaction output. A ScriptSig includes one or more signatures and additional data used for spending according to conditions that have been outlined in the output.

SDK

Stands for Software Development Kit - it provides all the necessary tools for a developer to create software on a specific platform.

Security Audit

An evaluation of how safe a specific system or blockchain is against attacks.

Security Token

A device which is used to grant access to a restricted resource and is given to investors after participating in an ICO.

Seed phrase

Represents a word collection that can be used to access a cryptocurrency wallet.

Segmented

Divided into segments.

Segregated Witness (SegWit)

A process which enables a higher number of transactions to be part of a block by separating them from coin-bitcoin transactions.

SegWit Wallets

Stands for Segregated Witness Wallets – a service that is executed on the Bitcoin blockchain and is concerned with separating particular transaction signature information. It can either be nested or native.

Selfish Mining

A strategy where blocks are withheld and released which could give the miner competitive advantage over the network.

Sharding

Dividing the network into several smaller component networks that can process transactions in parallel.

Signature

Defines a mathematical proof which shows that a private key or key shares have signed a transaction in a Digital Wallet. A single transaction can have from one to multiple signatures depending on the Wallet's parameters and authorization method. The signature prevents any further alterations on the transaction.

Simplified Payment Verification (SPV)

Represents a tool/software that can confirm that a cryptocurrency transaction has been added to the blockchain without the need to actually download the entire blockchain.

Single Signature (Single-Sig)

Defines a simple type of Digital Wallet authorization where the owner/user has one key and is the only person that can sign a transaction. These types of Wallets are very common and highly insecure. 

Smart contract

A self-executing contract with the terms of the agreement between buyer and seller being directly written into lines of code.

Social Login

A logging-in functionality which allows the user to apply their login information for various social networks and online platforms for other such. E.g. to log in to a website with Facebook.

Spoofing

Defines a type of attack in which a person or program falsifies another user's information and can successfully impersonate them in order to illegally obtain access to more of their data or account. 

Stablecoin

A digital asset that is intended to keep its stable value and not go through changes.

State Channel

An interaction channel between two participants, either users or blocks, on a network.

Solidity

A programming language used in the Ethereum blockchain for smart contract creation.

Sync

Short for synchronization. The process of equalizing the same information on two or more platforms/networks/devices.