人人能看懂的区块链底层技术简介

加密的奥义是上下文。比如“的”GBK编码是B5C4,用“高档”的加密算法固定变成100个字节,还是不够安全。破解者收集大量密文后进行统计,发现有100个字节出现次数非常多,那它就很可能对应“的”。然后再使用语言模型,如“我的”、“你的”都是高频词,再找出“我”、“你”等等。请浏览下:

机器没有智能,语言模型要靠大量的输入训练出来。我们可以用机器没见过的方式通信,例如“都都平丈我”代替“郁郁乎文哉” [出处],不说“茶”而说“如火如”,“Trump门”代表50…… [出处] 有没有更保险、更无趣、更数学的方法呢?

In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream, to give a digit of the ciphertext stream. Since encryption of each digit is dependent on the current state of the cipher, it is also known as state cipher. In practice, a digit is typically a bit and the combining operation is an exclusive-or (XOR). 在流式加密中,每个明文数字与密钥流的相应数字一次加密一个,以给出密文流的一个数字。由于每个数字的加密取决于密码的当前状态,因此也称为状态密码。实践中通常:一个数字通常是一个位,组合运算是异或(XOR)。

通信处理的单位叫符号symbol,密码学处理的单位叫数字digit,实际应用中一般是二进制的位bit.

不同上下文中“的”,加密后的密文不同,解密者就不好猜了。Binary stream ciphers are often constructed using linear-feedback shift registers. 状态state, 移位shift,听着就来劲。

A5/2 is a stream cipher used to provide voice privacy in the GSM (2G) cellular telephone protocol. It was used for export instead of the relatively stronger (but still weak) A5/1. It's an open secret that the privacy in GSM is compromised. The A5 set of ciphers it uses has been proven incapable of preventing data from being decrypted. The architecture of the standard makes it particularily vulnerable to man-in-the-middle attacks, and since all algorithms share a common key, the system is as weak as its weakest algorithm: A5/2. A5/2是一种流式加密,用于在GSM(2G)蜂窝电话协议中提供语音隐私。它被用于出口,而不是相对较强(但仍然较弱)的A5/1。GSM中的隐私被泄露是一个公开的秘密。事实证明,它使用的A5密码集无法防止数据被解密。该标准的体系结构使其特别容易受到中间人攻击,而且由于所有算法都共享一个公共密钥,因此该系统与最脆弱的算法A5/2一样脆弱。2G还容易收到伪基站发来的短信。有使用4G电话卡的老人手机,比如天语(K-Touch)的。智能机可以装老人桌面App。

还可以以块为单位加密。A block cipher is an encryption method that applies an algorithm along with a key to encrypt a block of text, rather than encrypting one bit at a time as in stream ciphers. For example, a common block cipher, AES, encrypts 128 bit blocks with a key of predetermined length: 128, 192, or 256 bits. 块加密是一种加密方法,它使用算法和密钥对文本块进行加密,而不是像流式密码那样一次加密一位。例如,通用分组密码AES使用预定长度的密钥对128位块进行加密:128、192或256位。“文本”、“位”,“分组”,又开始满天飞名词了。

Block cipher modes of operation have been developed to eliminate the chance of encrypting identical blocks of text the same way, the ciphertext formed from the previous encrypted block is applied to the next block. A block of bits called an initialization vector (IV) is also used by modes of operation to ensure ciphertexts remain distinct even when the same plaintext message is encrypted a number of times. 分组密码的操作模式已经被开发出来,以消除对相同文本块进行加密的可能性。同样的方法是,将前一个加密块形成的密文应用于下一个块。被称为初始化向量(IV)的比特块也被操作模式使用,以确保即使相同的明文消息被多次加密,密文也保持不同。

Cipher Block Chaining, or chained block encryption, is a block cipher mode of operation in cryptography. The use of a block cipher in which the bits of a given output block depend not only on the bits in the corresponding input block and in the key, but also on any or all prior data bits, either inputted to or produced during the enciphering or deciphering process. 密码块链或链式块加密是密码学中的一种分组密码操作模式。一种分组密码的使用,其中给定输出块的位不仅取决于相应输入块和密钥中的位,还取决于任何或所有先前的数据位,这些数据位要么输入到加密或解密过程中,要么在加密或解密过程中产生。

如果把链在一起的n个块看作一个大块,那么区块链加密可以看作大块加密或者超大块加密…… 吗?

数字签名不是说收到“今天下午放假。领导234577890090”,"234577890090"这样的签名复制粘贴,防伪性还不如手写的。而是类似"2324j;@@#$00jlasjlf1sfjl"这么一串,要解密后才能看到内容,领导无法否认他发过“今天下午放假。领导”,"2324j_改了几个字符"解密出来肯定不是“今天下午放假。领导”,很可能是一串乱码。

Blockchain.com is a bitcoin exchange, wallet and explorer service. Blockchain is a sequential distributed database found in cryptocurrencies derived from bitcoin. 加拿大最大比特币交易所陷入困境并拖欠用户近2亿美元-198 ... 比特币十年,五花八门交易所破产清单... 弄丢 103 枚比特币乌龙解决不了...

如果我拿比特币去买火箭炮。交钱了不发货,或者发货了不给钱,会怎样呢?所以我认为区块链是适合*做的事。它的一个很好应用是降低鉴定法律文书的成本,是高级的、数字的防伪技术。至于去中心化,个人或公司想和国家比算力?

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