Sec 9.1 - 9.4 due May 28th

What was difficult?

Following the algorithms were not all that hard. However, it is not easy to see what a "digital signature" is without actually seeing how it effects the document. At first I thought it was a little encoding appended to the end of the document (however as the book mentions) this would make it easy for an Eve to copy and past it anywhere she pleases. This would mean that the digital signature totally changes the actual message. It was hard for me to understand how one could get the message back, or how multiple people could sign a message. However, I am sure after going over the algorithms in class I will understand it.

Reflections

One of the things that was interesting was the mentioning of using the Birthday Attack to get someone to sign the hash of one document that had exactly the same hash of another document. It was interesting to see that it suggests changing the document before signing it which inhibits the birthday attack from succeeding. It seemed weird that such an attack can be thwarted by merely changing one character before signing.