Public Key Cryptography: Answers

Let us think about the answers to last week’s article questions on public key cryptography.

1. No, if you could work out the secret key from the public key then anyone would be able to decrypt the messages!
2. The public key is public knowledge anyway so you do not have to work it out.
3. Asymmetric encryption is faster as there is only one key. However, there is a problem in transferring the key, this must be done secretly as it holds the power to decrypt! This is an advantage of asymmetric encryption; keys do not need to be transferred.

This article was written by David Butler, one of the course creators and teachers at Oxbridge Inspire. David is studying for a PhD at the Alan Turing Institute in London.

If you enjoyed this article, you might consider coming to our course in Cambridge this summer on the Mathematics behind Cryptography.