1. Encryption Encryption is the process of obscuring information to make it unreadable without special knowledge. information http://en.wikipedia.org/wiki/Encryption Copyright © 2008 by Helene G. Kershner

2. Encryption is only a part! To ensure secrecy of a message one needs to be sure : To ensure secrecy of a message one needs to be sure :  the communication is secure  it is received by the right “people”  it can be decrypted (or decipher) In other words, we must verify the integrity and authenticity of a message. In other words, we must verify the integrity and authenticity of a message. http://en.wikipedia.org/wiki/Encryption Copyright © 2008 by Helene G. Kershner

3. Encryption Great Idea: A cipher is an algorithm for performing encryption (and the reverse, decryption) — a series of well-defined steps that can be followed as a procedure. algorithm  a cipher is a process  it is more than a secret code  WWII – COLOSSUS, Code Talkers Copyright © 2008 by Helene G. Kershner

4. Encryption The Government’s Need to Know Vs The Right to Privacy Which should have higher priority? Copyright © 2008 by Helene G. Kershner

5. Encryption Is this just a government vs the people type of issue? Why would ordinary citizens be interested in encrypting information? Copyright © 2008 by Helene G. Kershner

6. Encryption While encryption has been used to protect communications for centuries, until recently only organizations and individuals with an extraordinary need for secrecy have made use of it. While encryption has been used to protect communications for centuries, until recently only organizations and individuals with an extraordinary need for secrecy have made use of it. This changed in the 1970s This changed in the 1970s http://en.wikipedia.org/wiki/Encryption Copyright © 2008 by Helene G. Kershner

7. Encryption In the mid-1970s, strong encryption emerged from government agencies and moved into the public domain. In the mid-1970s, strong encryption emerged from government agencies and moved into the public domain. WHY? WHY? Copyright © 2008 by Helene G. Kershner

8. Encryption Where is it used if not by the government? Where is it used if not by the government? Encryption is now widely-used in computer systems such as Encryption is now widely-used in computer systems such as  Internet e-commerce, e-commerce  mobile telephone networks and mobile telephone mobile telephone  automatic teller machines. automatic teller machines automatic teller machines http://en.wikipedia.org/wiki/Encryption Copyright © 2008 by Helene G. Kershner