SHA-256有多少种组合? [英] How many combinations does SHA-256 have?

问题描述

通过使用在线工具和维基百科，我发现每个sha-256加密字符串都是64个字符长，包含数字和字符.因此，我假设存在34 ^ 36的组合(由代数计算器简化了2 ^ 216).经过研究，我发现大多数人说有2 ^ 256种组合.有人可以解释吗?为了使上下文更清晰，我写了一篇关于加密货币的论文，试图解释要加密多少种不同的组合，以及加密需要多长时间(因此需要多少猜测)，并将其与加密中的总原子量进行比较.宇宙(大约10 ^ 85).

By using an online tool and wikipedia I found out that every sha-256 encrypted string is 64 chars longs containing numbers and characters. Hence I assumed that there are 34^36 combinations ( 2^216 simplified by an algebra calculator ). After doing some research I found out that most people said there are 2^256 combinations. Could someone explain ? To make the context clear, I write a paper about cryptocurrencies and try to explain how many different combinations there are to encrypt and how long this could take ( therefore how many guesses it could take) and compare this to the amount of total atoms in the universe (roughly 10^85).

推荐答案

SHA-256生成256位，即32个字节(不是字符)，每个字节都有256个可能的值.

SHA-256 produces 256 bits which is 32 bytes, not characters, each byte has 256 possible values.

有256位，每个位有2个值(0或1)，即2 ^ 256.
有32个字节，每个字节有256个值，即256 ^ 32.
注意:2 ^ 256 == 256 ^ 32〜= 10 ^ 77.

There are 256 bits and each bit has 2 values (0 or 1), thus 2^256.
There are 32 bytes and each byte has 256 values, thus 256^32.
Note: 2^256 == 256^32 ~= 10^77.

可以用多种方式对32个字节进行编码，十六进制为64个字符，在Base64中为44个字符.

The 32 bytes can be encoded many ways, in hexadecimal it would be 64 characters, in Base64 it would be 44 characters.

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