Symmetric and Asymmetric Encryption

[@spectre_8690]

Cheers mate I ended up getting an 8 on the GCSE, thanks to you.

[@elmi8707]

3:45 if the bank encrypts something with the private key and sends it to a customer, can't this message be intercepted and decrypted by anyone who has the public key, making the communication insecure?

[@mxryxmk9834]

Thanks, great video! Next time could you please post a video with regards to how to program on pseudocode and python for beginners

[@RosettaTone]

Thanks for the help, this topic now makes a lot more sense! But i have 2 questions: With a key being public to everyone in Asymmetric encryption, does that mean anyone can interfere and decrypt the information sent by the bank, since the public key is public to everyone? And is it supposed to be that you can never read the data sent to the bank, but you can read the data being sent FROM the bank?

[@Wenedi]

Why hello there! Thanks for the 8 in cs :)

[@ammaarhtc]

I'm going into a level now. Would the videos you make for a level comp sci be finished this year

[@ammaarhtc]

Also I got grade 6 in the OCR comp sci exam

[@ammaarhtc]

Thanks mate

[@MrBrownCS]

That's great, well done! I haven't got a schedule, but probably not finished in 2018 but should be in the academic year

[@chemical_x5350]

I'm confused.... *Please help!* Session key is the one that is the secret key. Once it has been encrypted using the public key of the receiver, the sender will send the encrypted session key. So when the receiver receives it, he uses his private key to decrypt the session key. (which is the secret key) So next time the data is transfered, will the session key be used for both encryption and decryption? Since the same key is used to encrypt and to decrypt.

[@MrBrownCS]

Yes, this is all correct. A session key is used just between 2 people for a short period of time using symmetric encryption. The key needs to be shared secretly somehow, which is why asymmetric encryption is often used just for the key exchange (it is slower than symmetric but secure). In this process there are essentially 3 keys: public, private and session

[@chemical_x5350]

Computer Science Tutor So just for the purpose of exchanging the session key, assymetric encryption is used. And when this is done... *The sender and the receiver both use symmetric encryption for the rest of the data exchange* since the secret key has now been securely shared. Is that correct?

[@MrBrownCS]

@@chemical_x5350 Yes that's correct. Bear in mind that this isn't the only way to share a session key however, for example you can use a key distribution centre (KDC) and there are lots of different protocols that all work slightly differently to perform this session key exchange

[@chemical_x5350]

Computer Science Tutor thanks a lot for helping.. ❤️

[@keeganafonso1627]

is this for A-level or GCSE??