Spotlight on Ohlone:
O’Connell offers password safety tips

By Katheryn Dixon, Staff writer.

Thursday, October 22, 2009—Reprinted from Monitor.

Jeff O'Connell interacting with audience at Jackson Theatre. O'Connell interacts with students during his RSA Encryption Brown Bag Seminar on Monday. Ohlone students learned how to keep their passwords safe using public and private keys. —Photo by David Epperson.

Jeff O’Connell, Associate Professor of Mathematics, insisted throughout his Science Brown Bag Seminar on Friday that sixth-grade math was sufficient to grasp RSA encryption so as to enable someone to keep their Facebook password safe.

O’Connell must know genius sixth-graders. His one hour Power Point presentation at the Jackson Theatre was organized, effective and did reach out to the mathematically challenged at times, but ultimately, algorithms do not suffer fools kindly.

RSA is an algorithm for public-key cryptography which is used widely in electronic commerce. An algorithm is a method of solving a problem using a finite sequence of instructions.

O’Connell explained that RSA involves a public key and a private key.

Anyone can encrypt a message using the public key. However, only a private key can decrypt a message. RSA is part of everyday life on the internet.

O’Connell said, “The small letter padlock in the corner of a web browser uses RSA encryption to keep passwords and credit card numbers from being viewed while in transit to their destinations.”

First, he showed the audience how to generate the encryption key by first selecting two random prime numbers–“p” and “q.”

He then defined “n” which is the modulus for both the public and private keys and is computed as “n = pq.”

Jeff O'Connell. O'Connell after the seminar. —Photo by David Epperson.

He explained that the public key consists of modulus “n” and the public or encryption exponent “ e.” The private key consists of the modulus “n” and the private decryption exponent “d” which is kept secret.

Using quick multiplication and division requiring a calculator, O’Connell showed how to generate the key, encrypt a message and then decrypt it.

As a grand finale, he asked, “Can this encryption method be cracked? His answer: “Yes. Yes, but virtually impossible.”

He showed how to crack it by using factoring very large numbers, but did not do so.

He said, “Factoring humongous numbers is hard....It would take 70 years to break one cipher with all the computers in the world.”

RSA was developed in 1978 by Ron Rivest, Adi Shamir and Leonard Adleman at MIT.

MIT obtained a U.S. patent for RSA but released it into the public domain in 2002.

Finally, O’Connell showed the packed audience of about 300 students an excerpt of an Abbott and Costello film, “In the Navy” in which Lou Costello playing a Navy chef, explains his nonsensical mathematics formula on a blackboard over and over until it seems to make hilarious sense.

O’Connell said his next Brown Bag will be entitled “Math in the Movies and TV, Part 2, a Sequel.”

For review, O’Connell has provided a copy of the presentation online @

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