symmetric key

And in fact what we're going to talk about today is symmetric key algorithms.

And that was a huge security flaw because you have a symmetric key.

How exactly do both machines end up with the same symmetric key and keep it a secret?

And now I know what the symmetric key was.

Data Security based on public private a symmetric key.

First of all, remember that symmetric keys are - they used to be 64 bits.

Then we encrypt that with the second to the last symmetric key.

It does not break symmetric key technology, which is fundamentally simpler.

So back then the result was a symmetric key which was just too short.

The symmetric key is then used to encrypt the longer message.

You never said exactly what happens when the two machines need to create and exchange a new symmetric key.

The model is based around a block cipher with a secret symmetric key.

Well, chose a symmetric key size random number, which we know is, like, 128 bits.

But that just negotiates, remember, the symmetric key, which is much shorter.

It then uses the symmetric key to decrypt the file.

The reason we only need 256-bit or 128-bit symmetric keys is that it's an entirely different problem to crack it.

So you use the public key just to encrypt the symmetric key.

The receiver knows this key's secret 128-bit symmetric key.

Generates a fresh symmetric key for the data encapsulation scheme.

But then the symmetric key must be securely transported to the E-commerce site.

We encrypt that with the third to the last symmetric key, and so on, working our self back up the chain.

The last encryption we did was with its symmetric key, so it's able to decrypt it.

Instead they are often used to exchange symmetric keys, which are relatively short.

Note that the public key n is typically 1024-bits or even longer, thus much larger than typical symmetric keys.

This key is used to derive a unique 256 bit symmetric key for every single message.