Visualize Hashing and Salt as Part of Password Encryption Process

The image below is a simplified and easy-to-understand illustration of how hashing and salting work. The main takeaway from this post- multiple users can have the same password, but will all have different salt values, thus making their hash result value different, and when you authenticate, you authenticate by the hash result value of your passwords, which is virtually always going to be unique for each user record:

Simple, no?

Even in the case of 2 users having the same hash result, the usernames will/should not be the same, so you still have distinct accounts, because UserID is also checked in the authentication process.

Companies increasingly (and for good data privacy reasons) do not even store the clear text textbox value you enter when you sign up for and then log into Fb, Google, Amazon, etc- they check your entered password's hash result against the hash result they have for your user/account record either from when you registered or last changed your password.

Good answer to the question you may come across, "what is the difference between salt and an IV (initialization vector)?" (TL;DR: not all IV's are salt, but salt is a kind of IV): https://security.stackexchange.com/questions/6058/is-real-salt-the-same-as-initialization-vectors

Reference: https://www.slideshare.net/rahulrajatsingh/password-hashing-28725754

Blockchain

Blockchain, apart from all the hoopla heralding it as a "cryptic" means of facilitating monetary transactions, is essentially just a distributed digital ledger (multiple sources of the exact same truth) and distributed digital notaries (transaction verifiers) who, unlike human money handlers and human notaries- do not lie.

Transactions can be scheduled via any desired logic (ie. loan repayment terms, payroll distribution, annuity payouts, securities purchase/sale/options, etc.) and encryption lies at the foundation of the technology- ensuring data integrity and information security.

Blockchain is a type of DLT design. DLT is well-illustrated below:

© 2016 LPEA

Much like Git commits, each blockchain transaction is forever tied to an unmodifiable unique SHA-256 hash sum value that ensures the immutability (un-changeability) of each transaction- in brief, if the transaction changes, the original SHA-256 hash sum (unique file signature) that has already been distributed to all nodes of the blockchain- will not match the modified transaction's SHA-256 hash sum, and everyone connected to the blockchain will be able to see that someone is trying to commit a fraudulent transaction modification. So changes to already-posted transactions within a blockchain digital ledger (in theory at least) are virtually impossible.

Reference Video: https://anders.com/blockchain/

Symmetric Encryption

Symmetric encryption is used in electronic communication as a means to:

(1): Take visible-to-humans data

(2): Scramble the plaintext data with a mathematical byte-rearranging cipher algorithm (unlockable only via a secure cryptographic key) to make it unreadable/invisible-to-humans while it’s being stored on a disk or transmitted over a network

(3): Unscramble the encrypted data with the required cryptographic key when it’s needed, making it visible-to-humans, but only for the key-holding recipient(s).

Encryption's Purpose: it enhances security by limiting data loss even if access controls are bypassed. For example, if the database host computer has vulnerabilities and a hacker obtains sensitive data, that stolen information might be useless if it is encrypted.

Reference: https://stackoverflow.com/questions/10168240/encrypting-decrypting-a-string-in-c-sharp