so one of the most important differences in encryption is symmetric versus asymmetric encryption.
and it's really important to understand what that means and the implications of both and what they are supposed to do.
so at the highest level, symmetric encryption versus asymmetric is really a difference of the amount of keys used in asymmetric encryption.
you have two different keys, a public key, which can be shared out to anyone and a private key, which should be kept secret.
it actually has to be kept secret.
because if someone has your private key, well, they can decrypt anything.
asymmetric encryption is more secure, but it's more, it's more expensive in terms of time and the cost computationally to actually compute and decrypt things.
that's because you're using two different separate keys and it costs a little bit more time on a computer to actually decrypt it.
symmetric encryption on the other hand, only involves one key.
this key is shared amongst all the parties that need to encrypt and decrypt data.
it's very fast and less expensive on the computer and in terms of time, but it's a little less secure because if that single key does get compromised, well, then you, then all of the encrypted data becomes compromised as well.
so you have to be very careful how you're sharing that one key.
and especially over the internet today, if you're trying to share a single key, it's very risky to share it if it's not encrypted itself.
so it can get a bit confusing on well, how do modern systems do it?
well, they use a mix of both.
so almost no encryption standard is going to use just one or the other.
if you look at something like tls, which the internet uses for normal web browsing, it actually uses both asymmetric for the key exchange and then symmetric encryption to use that key.
so to use asymmetric to exchange a key securely, and then it will take that key and encrypt the rest of the traffic with the web session using that single key.
so it's important just to know at a high level, the differences between the two and that both are used in almost everything when it comes to encryption.
even later in this course, we'll talk about pgp and pgp uses both forms of encryption.
the normal internet uses both forms of encryption.
if you're streaming stuff over the internet, you'll use symmetric.
if you're encrypting data at rest, just sitting on a hard drive, you'll use asymmetric, for example.
and those are just some high level examples.
you can get really specific on when and why to use certain types of encryption methods and especially what types of encryption.
so some examples, if you're familiar with some encryption ciphers or encryption algorithms, here's some on the screen here.
but like we talked about, pgp primarily uses asymmetric, although it will use symmetric in some cases.
you have ecc, rsa, diffie- hellman.
these are all asymmetric types of key exchanges and key encryption.
and then you have symmetric aes two fish, des, rc four.
if you don't know any of these, don't worry.
all of them do slightly different things.
they have different types of algorithms, implement key exchanges differently.
the way they encrypt might be different.
so it doesn't really matter, but it's good to recognize these names with the type of encryption they are.
hopefully that gave you a good baseline understanding of symmetric versus asymmetric encryption.
if you have any questions, let me know.
otherwise see you in the next one.