Secure Hash Algorithms Concepts hash functions · SHA · DSA Main standards SHA-0 · SHA-1 · SHA-2 · SHA-3
SHA-2 General Designers National Security Agency First published 2001 Series (SHA-0), SHA-1, SHA-2, SHA-3 Certification FIPS PUB 180-4, CRYPTREC, NESSIE Detail Digest sizes 224, 256, 384, or 512 bits Structure Merkle–Damgård constructionwith Davies–Meyer compression function Rounds 64 or 80 Best public cryptanalysisA 2011 attack breaks preimage resistance for 57 out of 80 rounds of SHA-512, and 52 out of 64 rounds for SHA-256. Pseudo-collision attack against up to 46 rounds of SHA-256.
SHA-256 and SHA-512 are prone to length extension attacks. By guessing the hidden part of the state, length extension attacks on SHA-224 and SHA-384 succeed with probability 2−(256−224) = 2−32 > 2−224 and 2−(512−384) = 2−128 > 2−384 respectively.SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA). They are built using the Merkle–Damgård structure, from a One-way compression function itself built using the Davies-Meyer structure from a (classified) specialized block cipher.Cryptographic hash functions are mathematical operations run on digital data; by comparing the computed “hash” (the output from execution of the algorithm) to a known and expected hash value, a person can determine the data’s integrity. For example, computing the hash of a downloaded file and comparing the result to a previously published hash result can show whether the download has been modified or tampered with. A key aspect of cryptographic hash functions is their collision resistance: nobody should be able to find two different input values that result in the same hash output.SHA-2 includes significant changes from its predecessor, SHA-1. The SHA-2 family consists of six hash functions with digests (hash values) that are 224, 256, 384 or 512 bits: SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256.SHA-256 and SHA-512 are novel hash functions computed with 32-bit and 64-bit words, respectively.
I decided I would not Invest in Bitcoin, I had been studying it very closely for about a year but ultimately felt it was not what I was looking for in line with my own political stance with respect to Monetary reform and provision of Credit and liquidity into democratic debt free community economies.
You heard about Crypto Currencies,
Richard Stallman the founder of GNU describes what free software is.
´´Free software means the users have the freedom to run, copy, distribute, study, change and improve the software.Free software is a matter of liberty, not price. To understand the concept, you should think of “free” as in “free speech”, not as in “free beer”.
More precisely, free software means users of a program have the four essential freedoms:
- The freedom to run the program as you wish, for any purpose (freedom 0).
- The freedom to study how the program works, and adapt it to your needs (freedom 1). Access to the source code is a precondition for this.
- The freedom to redistribute copies so you can help your neighbor (freedom 2).
- The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (freedom 3). Access to the source code is a precondition for this.
Money is not valuable in and of itself, Money is a ticket or coupon for exchange / deferred consumption and the value and wealth lie in the economy within which a token/Coupon Unit of account is valid for trade within.
Aristotle said money is created by Law not nature, this is true of FIAT money. Bitcoin and cryptocurrencies are presently created by convention or custom within a defined network lets call it the Blockchain space. Crypto is voluntary and very powerful but a very small fish in an ocean of FIAT money.
When Bitcoin or ETHER or Dash or any of the hundreds of COins are generally accepted and held in preference to other Money´s with STate/central bank sanction then the Bankers will have lost. Things are a far way from that point as most of the Greater Fool investment in the present bubble is not an investment but speculation where The speculator takes profits in FIAT currency, ultimately this ties Bitcoin to FIAT value which in itself is also illusory.
Carol Quigley sums up the idea of Moey and wealth in Tragedy and Hope thus,
Money and Goods Are Different
”Thus, clearly, money and goods are not the same thing but are, on the contrary,
exactly opposite things. Most confusion in economic thinking arises from a failure to
recognise this fact. Goods are wealth which you have, while money is a claim on wealth which you do not have. Thus goods are an asset; money is a debt. If goods are wealth; money is not wealth, or negative wealth, or even anti-wealth. They always behave in opposite ways, just as they usually move in opposite directions. If the value of one goes up, the value of the other goes down, and in the same proportion.”
The Relationship Between Goods and Money Is Clear to Bankers
In the course of time the central fact of the developing economic system, the
relationship between goods and money, became clear, at least to bankers. This relationship, the price system, depended upon five things: the supply and the demand for goods, the supply and the demand for money, and the speed of exchange between money and goods. An increase in three of these (demand for goods, supply of money, speed of circulation) would move the prices of goods up and the value of
money down. This inflation was objectionable to bankers, although desirable to producers and merchants. On the other hand, a decrease in the same three items would be deflationary and would please bankers, worry producers and merchants, and delight consumers (who obtained more goods for less money). The other factors worked in the opposite direction so that an increase in them (supply of goods, demand for money, and slowness of circulation or exchange) would be deflationary.”