In the prime video on cryptocurrencies, I started two references to situations where, in order to break a thrown part of security, you would have to guess a specific string of 256 flecks. One of these was in the context of digital signatures and the other in the context of a cryptographic hash office. For pattern, if you want to find a message whose SH-A2 56 hash is some specific string of 256 fragments, you have no better method than to merely guess and check random words, and this would require, on average, 2^ 256 suspects. Now this is a number so far removed from anything that we ever deal with that it can be hard to appreciate its length. But let’s give it a try. 2^ 256 is the same as 2^ 32, multiplied by itself 8 epoches. Now what’s nice about that split is that 2^ 32 is 4 billion. Which is at least a number we can think about, right? It’s the kind of thing you might see in a headline. So what we need to do is appreciate what multiplying 4 billion times itself 8 succeeding hours really feels like. As many of you know the GPU on your computer can let you run a whole cluster of computations in similarity fantastically quickly.So if “youre supposed to” specifically planned a GPU to run a cryptographic hash serve over and over, a really good one might be able to do a little less than a billion hashes per second. Let’s say that you just take a bunch of those and cram your computer full of extra GPUs so that your computer can run 4 billion hashes per second. So the first 4 billion here is going to represent the number of hashes per second per computer. Now, photo four billion of these GPU-packed computers. For comparison, even though Google does not at all make their number of servers public, reckons have it somewhere in the single-digit millions. In world, most of those servers are going to be much less powerful than our imagined GPU-packed machine. But let’s say Google ousted all of its millions of servers with a machine like this. Then four billion machines would convey about a thousand copies of this souped-up Google. Let’s call that one KiloGoogle worth of computing power. There’s about 7.3 billion people on Earth, so next imagine uttering a little over half of each individual on Earth their own personal KiloGoogle.Now, imagine four billion copies of this Earth. For purposes of comparison, the Milky way system has somewhere between 100 and 400 billion idols. We don’t really know, but the estimates tend to be in that range. So this would be akin to a full 1% of every idol in the galaxy, having a copy of Earth, where half the people on that Earth have their own personal KiloGoogle. Next, try to imagine 4 billion copies of the Milky Way.And we’re going to call this your GigaGalactic Super Computer, ranging about 2^ 160 guess every second. Now four billion seconds? That’s about 126.8 years. Four billion of those? Well, That’s 507 billion years, which is about 37 seasons the age of the universe. So even if you were to have your GPU-packed KiloGoogle per person multiplanetary GigaGalactic computer judge numbers for 37 terms the age of the universe, it would still exclusively have a 1 in 4 billion probability of see the redres guess. By the channel, the nation of Bitcoin hashing these days anything else of the miners put together guess-and-check at a rate of about five billion billion hashes per second. That corresponds to one-third of what I time described as a KiloGoogle. This is not because there are actually billions of GPU-packed machines out there, but because miners actually use something that’s about a thousand times better than a GPU – Application Specific Integrated Circuits. These are bits of hardware specifically designed for Bitcoin mining, for ranging a cluster of SH-A2 56 hashes and nothing else. Turns out, there’s a lot of efficiency gains to be had when you throw away the is essential for general arithmetic, and layout your integrated circuits for one and only one task.Also, on matters of large the competence of two that I personally find it hard to get my spirit around, this channel recently outshone 2^ 18 customers, and to engage a little more with some sub-portion of those 2^ 18 parties, I’m going to do a Q& A session. I’ve left a relate in the description to a Reddit thread where you can post questions and upload the ones you want to hear answers to, and probably in the next video or on Twitter or something like that, I’ll announce the format in which I’d like to give rebuttals. See you then ..