Using the Caesar cipher and a public key, pairs of participants will send encrypted messages to each other in full view and hearing of other eavesdropping participants in the group, who will race to decrypt the messages before the intended recipient.
Pairs of participants will then attempt to establish a shared, secret key while others eavesdrop. Previous creative solutions have involved sign language and interpretive dance!
Diffie-Hellman will be introduced as a secure algorithm for key exchange. Pairs of participants will follow this method and agree on a shared, secret key which eavesdroppers will be unable to guess.
The group will discuss topical issues involving encryption including the Investigatory Powers Bill, backdoors, and messaging apps such as WhatsApp.
This is a Shed session.