Asymmetric Key Cryptography: The RSA Algorithm by Hand

This video demonstrates the underlying principles of the RSA cryptosystem. It shows how the public and private asymmetric keys can be calculated from a pair of prime numbers. It also shows how to encrypt a message using the public key, and decrypt it using the private key. For ease, the calculations are performed with a spreadsheet, because the numbers involved in the process can be very large. The video points out that once a pair of asymmetric keys has been generated, the selection of which key should be made public and which key should be private, is arbitrary because RSA is a trap-door process.