Essentially, the video is a story about the development of some important cryptographic cyphers.
One team in England led by a British government defence agency
One team in the United States led by university researchers

The following text and links describes the content of the video.

intro
"Cryptography has fundamentally changed the course of history"
- example the enigma code machine  www.kemble.org.uk/enigma.html
- every code ever devised suffered from a flaw - the difficulty of sending the key to translate the message
- the "key distribution" question is the oldest problem in Cryptography
- the key is the special recipe for first scrambling, then un-scrambling a message
- the problem of keeping the key away from danger is very expensive
- involved couriers and special armed messengers

Stanford - the idea was to challenge the convention that the sender take responsibility for the encryption
Diffie and Hellman proposed that the receiver take responsibility for the encryption

 
Narrator - mathematical locks are easy to make, but hard to undue - difficult to reverse
- multiplying 2 large numbers is the mathematical equivalent of a lock
- working it backwards is very very difficult

CESG Communications Electronic Security Group in U.K. James Ellis of CESG developed the innovative cryptographic idea 5 years before Diffie and Hellman in the U.S. 1973 Clifford Cocks - he took a fresh approach - doing advanced mathematics in his head, Cocks came up with a revolutionary formula

MIT mentioned in the video
- at the labs of MIT, in the spring of 1976, Rivest, Shamir, and Adelman read the Diffie-Hellman paper "New Directions in Cryptography." The three then decided to set out making a multi-user cryptography system.
Rivest Shamir Adleman (RSA)
RSA is a public key cryptosystem for both encryption and authentication.
It was invented in 1977. It is an encryption algorithm that uses very large prime numbers to generate the public key and the private key.
- most credit card information encrypted with the RSA process
- meanwhile the Brits kept their silence for two decades more
- the Americans who created RSO were not the first to create public key encryption, but they were the first to bring it out in the open, and, they made a lot of money

The video ends with the line

"Cryptography - The science of secrecy is no longer a secret science"
 
 

A place on the RSA website to get great info on crypto topics