Schlagwort-Archive: meme

What Blockchain Really Is

Blockchain is not a technology, it is a meme. The legend of a magical technology about to disrupt everything – e-very-thing! – emerged from an ecosystem of investment fraud, where it was originally used to sell worthless coins and tokens to the gullible. The blockchain legend did not have to make sense to fulfill this purpose, quite to the contrary.

Due to media fascination with the speculative bubble formed by Bitcoin and other crypto-“currencies”, the blockchain legend spilled over into the real business world. It had everything it needed to spread: great promises instilling fear of missing out, explanations one could replicate by memorizing rather than understanding, and holes in just the right places that everyone could fill with their personal visions.

Application proposals, unsurprisingly, revolved around what people experienced in their everyday lives, such as tracking bananas from the farm to the supermarket or making payments. The blockchain legend would have worked just as well with any other alleged use case, as it did not promise any specific advantages compared to actual technology.

As a meme, the blockchain legend can spread only among those who want to believe, or at least accept the proposition that blockchain were a technology. The moment one understands the true nature of blockchain as a redundantly-decentrally spread meme one stops spreading the meme.

Two years have passed since peak blockchain. Fewer and fewer people continue to propagate the meme. I can see the light at the end of the tunnel.

Something to ponder

Which of the following statements do you agree or disagree with, and why?

  1. If you get robbed, it’s your fault. You should have carried a gun and used it to defend yourself.
  2. If your home gets burgled, it’s your fault. Your should have secured your home properly.
  3. If you get raped, it’s your fault. Your shouldn’t have worn those sexy clothes, and hey, what were you doing in that park at night?
  4. If your computer gets hacked, it’s your fault. You should have patched the computer every day and used a better password.
  5. If you get run over by a car and injured in the accident, it’s your fault. You should have worn a helmet and a high-viz jacket.
  6. If someone bullies you on the Internet, it’s your fault. You should have used a pseudonym on Facebook.

Do you agree with all, some, or none of these statements? Please elaborate in the comments. I’m not so much interested in nitpicking about the causation of certain incidents – read »your fault« as »in part your fault« if you like so. What interests me rather is the consistency or incocnsistency in our assessment of these matters. If you happen to agree with some of the statements but disagree with others, why is that?

P.S. (2014-09-05): Samuel Liles and Eugene Spafford discuss this matter more thoroughly: What is wrong with all of you? Reflections on nude pictures, victim shaming, and cyber security

25 Random Facts

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Mostly out of my head; feel free to correct me if you spot an error:

  1. d1901fa3176ffd7d77f2cd4dde125829
  2. The most common use for random data in computer security is as a secret: a password, a key, or a session ID for instance.
  3. Random data is the result of a random process.
  4. An ideal toss of a coin generates 1 bit of random data. [Update 2009-11-27: Or maybe not.] For n tosses there are 2n different strings of n bits that could be the result.
  5. Producing random data is hard on a mostly deterministic machine, particularly if large quantities are needed.
  6. Data that looks random doesn’t have to be. For example, base64-encoded data looks random to some people although it isn’t.
  7. The output of a random process has certain statistical properties that can be tested.
  8. A deterministic process can produce output that exposes the same statistical properties as a truly random process for any finite number of bits.
  9. It is therefore impossible, for any finite string of bits, to prove that it is the result of a random process.
  10. It is, however, possible to detect and reject as non-random the results of some deterministic processes on the basis of statistical tests.
  11. A deterministic process designed to produce output that passes some of the statistical randomness tests is called a pseudorandom number generator (PRNG).
  12. There are different qualities of pseudorandom number generators. The simpler ones are unsuitable for security applications.
  13. Data from a PRNG that looks random according to statistical test can still be entirely predictable if the PRNG is known and its internal state can be worked out.
  14. The whole point of using random data in security is to make guessing hard. The idea is that to guess a random secret an attacker will have to search the entire space of possible values in the worst case and half of it in the average case.
  15. Attackers cannot be prevented from guessing secrets. If there is an easier way than guessing, the attacker is assumed to prefer the easier way.
  16. The inner state of some PRNGs can be determined from a small number of subsequent output values.
  17. Up to a certain length and under a number of side conditions, the output of cryptographic primitives such as hash functions or ciphers are expected to expose the statistical properties of random data.
  18. Pseudorandom number generators for security purposes often combine a source of random data with cryptographic methods to produce an almost arbitrary amount of random data. True random data is used to seed the generator, which then expands the data.
  19. Potential sources of random data in a deterministic computer system are external events and digitized noise from analog circuits.
  20. Using digitized noise isn’t easy either. The process might be biased, limiting the randomness obtained.
  21. Humans are poor random number generators unless they execute a random process, e.g. repeatedly tossing a coin.
  22. Stream ciphers combine a (pseudo)random key stream with the data stream using bitwise XOR.
  23. A string of truly random data as a message has maximum entropy. Such random data thus cannot be compressed.
  24. Random data can also be used as test input into software components. This type of testing is called fuzzing.
  25. For an ideal block cipher, flipping a single bit in either the clear text or the key flips each bit of the cipher text with probability 0.5.

Note that I’m sloppy in my use of the term random. Randomness can mean a lot of different things and I’m really making a few assumptions.