Via Schneier. Scroll down and read the quote, there’s not much point to summarizing.
As the saying goes… “Find Another Way.”
Eschatology: Bitcoin is probably the only self-regulating securities market in the world… self-regulating in that the exchanges limit the rate-of-fall by crashing under the load whenever the market moves too quickly.
(As it did today — a guy gave away 13,000 USD worth of Bitcoins to random people on Reddit, triggering a sell-off that temporaríly cut the value of Bitcoins in half and wiped out a billion dollars’ worth of market capitalization in the space of a few hours. Abbie Hoffman would be proud: http://articles.businessinsider.com/2011-10-03/politics/30237871_1_abbie-hoffman-dollar-bills-wall-street-protest
It’ll probably go back up, at least in the short term. The real value of Bitcoin (especially to the mildly wealthy) is that it allows people to transact money with a guarantee of no interference, and a lot of very paranoid rich people are extremely afraid of “capital controls” in the near future that would force them to keep their money in one place. That this comes at the cost of recording their transactions publicly forever is lost on a lot of them, which may make for some amusing headlines someday.)
Gold: Um, maybe a better hedge than I thought: http://bullmarketthinking.com/comex-gold-inventories-collapse-by-largest-amount-on-record/
“Alice and Bob procure the same edition of the white pages book for a particular town, say Cambridge. For each letter Alice wants to encrypt, she finds a person in the book whose last name starts with this letter and uses his/her phone number as the encryption of that letter.
To decrypt the message Bob has to read through the whole book to find all the numbers. The decryption will take a lot more time than the encryption. If the book increases in size the time it takes Alice to do the encryption almost doesn’t increase, but the decryption process becomes more and more draining.
This example is very good for teaching one-way functions to non-mathematicians. Unfortunately, the technology changes and the example that Micali taught me fifteen years ago isn’t so cute anymore. Indeed you can do a reverse look-up online of every phone number in the white pages.
I still use this example, with an assumption that there is no reverse look-up. I recently taught it to my AMSA students. And one of my 8th graders said, “If I were Bob, I would just call all the phone numbers and ask their last names.””