28 OCT 2024 by ideonexus

## Quantifying Information Content Does Not Bring Meaning Fr...

It is perfectly true that redundancy aids recognition of a signal as a language or a code, and this recognition is crucial to SETI. However, Shannon’s method provides only a quantitative measure of the complexity of a language or signaling system—not a translation. And while it is axiomatic in cryptology that redundancy helps in deciphering a text, the task of decipherment/cryptanalysis is to move from an encoded text to the original text—not from text to meaning. To get from text to me...We may be able to quantify the information content of an alien signal, but that is very different from deriving the meaning from the signal.

28 SEP 2021 by ideonexus

## Prime Numbers and Cryptography

Algorithms for finding prime numbers date back at least as far as ancient Greece, where mathematicians used a straightforward approach known as the Sieve of Erastothenes. The Sieve of Erastothenes works as follows: To find all the primes less than n, begin by writing down all the numbers from 1 to n in sequence. Then cross out all the numbers that are multiples of 2, besides itself (4, 6, 8, 10, 12, and so on). Take the next smallest number that hasn’t been crossed out (in this case, 3), an...27 JUL 2018 by ideonexus

## Redundancy of English language is a Goldilocks zone for C...

In Shannon’s terms, the feature of messages that makes codecracking possible is redundancy. A historian of cryptography, David Kahn, explained it like this: “Roughly, redundancy means that more symbols are transmitted in a message than are actually needed to bear the information.” Information resolves our uncertainty; redundancy is every part of a message that tells us nothing new. Whenever we can guess what comes next, we’re in the presence of redundancy. Letters can be redundant: be...25 OCT 2017 by ideonexus

## Blockchains

Ownership on the Bitcoin blockchain is determined by a pair of cryptographic keys. The first, called the public key, resides in the blockchain for anyone to see. The second is called the private key, and its owner keeps it safe from view. The two keys have a special mathematical relationship that makes them useful for signing digital messages. Here’s how that happens: Helmut takes a message, combines it with his private key, does some calculations, and ends up with a long number. Anyone who...05 MAR 2015 by ideonexus