[Response to question #1] When Singh says that "a weak encryption can be worse than no encryption at all," it makes me want to equate it to a devastating mistake of leaving an unmistakable trace because with that, all of the evidence of enciphering a message to plot to kill Queen Elizabeth falls completely onto Queen Mary of Scots because of the cipher that was used on both sides. Whereas if there was no encryption, there could be more room (just a little) for the argument that the letters between Mary and Babington could just be in the wrong place at the wrong time (though it looks very unlikely to win over in this Mary-Elizabeth case). For example, if Mary and Babington were not too ignorant or overconfident with the security of their enciphered messages, they could agree on the word “She” with a capital S in place of saying the “Queen” (or any word/phrase that makes the plot to assassinate Elizabeth obvious) because then, the plot to kill can be against anyone. However, when both Mary and Babington use the exact same cipher and have the exact same content of their intentions, it becomes very difficult to convince people of her innocence. My interpretation of having no encryption as opposed to a weak encryption is that with an encryption, albeit furtive, can do more damage than good when it falls into the wrong hands especially with high stakes because it implies that there is information that is so valuable that it has to be hidden from others' eyes. This heightens the curiosity and thus makes people, whether for good intention or bad, feel the need to pry into the message and know its meaning. Also in Mary’s case, it presented itself as undeniable evidence that she was taking part in the Babington conspiracy and ultimately her cause of death.
One of the things which stood out to me throughout the book Little Brother was how it was so easy for even everyday people to foil the security measures put in place by the Department of Homeland Security. One of my personal favorites was the "arphid cloners" which could replace all of the electronic information on things such as your credit cards and identification and replace that with those of someone else. A particular passage showcasing this was when Marcus' father came home after being pulled over and questioned twice. This occurred because his father had been all over town recently to many various places, or so the DHS thought from their surveillance data. His father really had done nothing wrong, but various people who had been "given" his identity were making it look like he had very odd travel patterns. This marked a turning point in the novel as Marcus' father finally realized that there were some potential downsides to all of this surveillance the DHS was performing.
This concept of messing with security goes far beyond this one specific type of exploit, and goes further than the book as well. Every method of surveillance must have some weakness, whether that be an ability to avoid it or to attack it with so much information it cannot sort through it all properly. That raises the question of how useful every surveillance implement of the government is in the real world. It is possible that any day a random group of people could come up with a method to completely mess with some form of NSA surveillance. However as seen in the book, it is us as citizens who are the ones that are punished when there are flaws in surveillance systems. Thus we must ask ourselves if we are truly comfortable continuing to give up some of our privacy to groups such as the NSA and if that our relinquishing some of our right to privacy is actually helping in any way at all.