Key stretching

- [Instructor] Many encryption technologies…depend upon the ability to create an encryption key…from a password in a way that remains strong.…Key Stretching technologies allow this to happen.…The basic idea behind Key Stretching…is that an algorithm takes a relatively insecure value,…such as a password, and manipulates it…in a way that makes it stronger…and more resilient to threats like dictionary attacks.…Key Stretching combines two different techniques…to add strength to an encryption key.…

First, it combines encryption keys…with a value known as a salt, to modify the key.…This process is known as Salting.…Second, it hashes the resulting value…to add time to the key-checking process.…This might be less than a second,…but Key Stretching algorithms repeat this process…hundreds or thousands of times…to consume longer amounts of time.…The idea is, that if the user knows the correct password,…the second or two that it takes…to verify the password is not a big deal.…

However, if an attacker is trying…to guess the correct password,…