randombit's New Writeups

junk silver (thing)

2008-12-13T01:18:10Z

Junk silver is an informal term for any silver coin which is in sufficiently poor condition to have no special value to a collector or numismatist. The market price for these coins is based on their "melt value" - the value of the silver they contain. Thus they are considered a cheap and relatively easy way of investing in silver.

Modern coins are composed of cheap metals like copper and nickel. Looking historically this is an aberration; the gold ducat was in wide circulation in Europe from the 1200s until just before World War I. After most nations came off the gold standard during the Great Depression, these coins quickly vanished from circulation, as predicted by Gresham's Law. Silver remained in use for regular everyday coinage for a bit longer - dimes, quarters, and half-dollars were composed mostly silver until 1964 in the United States, and until 1967 in Canada.

Many of these old silver coins were melted down in the late 1970s, when the Hunt Brothers…

Reentrant (idea)

2006-05-31T13:13:03Z

Reentrancy is a term in computer programming with the meaning that there is the possibility that at a single point in time a particular piece of code might be in the process of executing multiple times (thus, "re-entered"). This most commonly occurs in multithreaded code, though programs which make use of recursive algorithms also often cause reentrant conditions.

What we normally think of as a function (from a mathematical standpoint) can be reentrant without issue - one can compute 2*sin(x) given an input x as many times as you like in parallel without any concerns. In programming, reentrancy can be a problem, because of state; this leads to interactions where the behavior of one piece of code depends on what another one did (or hasn't done). Without this shared state, two pieces of code cannot observe each other in any way, so it would be impossible for them to depend on one another, even if they wanted to - they have no way to communicate with each other,…

pork and pineapple tacos (thing)

2005-12-11T16:30:11Z

These are delicious, and great for casual group meals. I learned the recipe from an old roommate from Santa Fe, who learned them from his old-timer neighbor. Supposedly this is a fairly 'legit' Mexican recipe; I have no way of knowing (Ouroboros directed me to tacos al pastor, which seems to be the original form - the variant that follows in this node was obviously Americanized to some extent).

Ingredients (makes 10):

10 corn tortillas
Vegetable oil
1 can refried beans
1 lb of of pork, cut into small pieces. I normally use pork chops because they're easy to deal with.
A 20 oz can of pineapple chunks, drained
A good handful of cilantro, washed and finely cut, with the stems removed
Salsa, ideally something chunky and spicy
A bottle of hot sauce (I prefer Cholula)
Lime wedges (you'll need them for the beer anyway, might as well have a lot)
(optional) Grated cheese (cheddar or Jack being obvious choices)

…

SSL and TLS (thing)

2005-11-20T22:33:40Z

Title: SSL and TLS: Designing and Building Secure Systems
Author: Eric Rescorla
Pages: 499
Publisher: Addison Wesley
ISBN: 0-201-61598-3
List price: $44.99
Summary: A good reference if you need to implement SSL or TLS, but otherwise not terribly useful to most people.

SSL and TLS is a pretty specialized book - it covers how to implement and use the network security protocols SSL and TLS (which are essentially the same thing, actually) to help provide confidentiality, integrity, and non-repudiation though judicious use of cryptography. The author, Eric Rescorla, is co-chair of the IETF's TLS working group (in addition to being a member of the Internet Architecture Board), and has implemented the SSL/TLS protocol at least twice, so he knows the area pretty darn well.

The book is an excellent companion to the RFCs which describe the protocol, though at points it really seems like…

If an attacker has physical access, your system is already compromised (idea)

2005-11-06T19:22:50Z

This is often stated as some sort of truism, but in fact this is just a statement that often happens to be true, rather than some immutable law of computers. You might equivalently say things like "All software sucks" or "Sex is fun" or "Milkshakes taste good". These are all generally true, and counterexamples are rare, but that does not mean that they are universally correct. Just like sometimes you find a good piece of software or get a bad milkshake, you can build systems such that physical access gains an attacker very little, if anything. It's expensive and takes a lot of work, but you can do it. For most uses, it is not worth that effort, since most computers are not really that valuable, nor are they placed anywhere that an attacker will normally be able to access them (your house, a colocation facility, etc). On the other hand, devices such as ATMs are both in vulnerable public locations and have a great deal of intrinsic value -- in the case of ATMs, that is not so…

Knob Creek (thing)

2005-06-19T21:51:16Z

Knob Creek, named after a creek near where Abraham Lincoln grew up, is one of the four "Small Batch Bourbons" produced by Jim Beam (the others being Basil Hayden's, Booker's, and Bakers). These four, along with Maker's Mark, are generally considered to be the "middle class" of bourbon; vastly superior to Jack Daniel's, Wild Turkey, Old Granddad, and friends, but not falling into the extremely expensive, specialty range. The major selling point for Knob Creek is that it is aged for 9 years (most bourbons are aged between 4 and 8 years) in charred white oak barrels, which (supposedly) gives Knob Creek its excellent smoothness and flavor (I am willing to attest to the taste, just not that it is due to the length or manner of aging). Bottled at 100 proof, Knob Creek is strong, but extremely smooth. It has a noticeable sweetness, but the sweetness is not cloyingly strong, as I find many cheaper bourbons and whiskeys to be. There is also a distinctive taste…