Symmetric encryption

- [Instructor] Symmetric encryption algorithms…are computationally fast,…meaning computers are very quick and very efficient…in performing the math associated with symmetric encryption.…Now recall you often hear this referred to…as private key encryption.…One of the drawbacks of symmetric encryption…comes from scalability associated…with large numbers of unique keys.…There's an equation used to calculate…based on n number of people trying to communicate,…how many different symmetric encryption keys would you need?…And that's this equation you see here.…

Let's through in examples so we can see…what that really looks like.…So say we have a group of five people.…We've got Bob, Jon, Alice, Steph, and Sue…and all five of them want to talk to each other.…So for Bob and Jon to talk to each other in a secure manner…using symmetric encryption,…they have to have a symmetric key…between the two of them.…For Bob to talk Steph is in a different symmetric key.…For Stephanie to talk back to Jon…is a different symmetric key.…You see all the lines we start to have going…