MD5还广泛用于操作系统的登陆认证上,如Unix、各类BSD系统登录密码、数字签名等诸多方。如在UNIX系统中用户的密码是以MD5(或其它类似的算法)经Hash运算后存储在文件系统中。当用户登录的时候,系统把用户输入的密码进行MD5 Hash运算,然后再去和保存在文件系统中的MD5值进行比较,进而确定输入的密码是否正确。通过这样的步骤,系统在并不知道用户密码的明码的情况下就可以确定用户登录系统的合法性。这可以避免用户的密码被具有系统管理员权限的用户知道。MD5将任意长度的“字节串”映射为一个128bit的大整数,并且是通过该128bit反推原始字符串是困难的,换句话说就是,即使你看到源程序和算法描述,也无法将一个MD5的值变换回原始的字符串,从数学原理上说,是因为原始的字符串有无穷多个,这有点象不存在反函数的数学函数。所以,要遇到了md5密码的问题,比较好的办法是:你可以用这个系统中的md5()函数重新设一个密码,如admin,把生成的一串密码的Hash值覆盖原来的Hash值就行了。


As a merchant one of your main goals is to be able to accept and process payments as quickly and seamlessly as possible so you can make your customers happy and receive payments without any headaches. Bitcoin Cash is the solution, as it has fast and low-cost transactions. As the world goes digital, electronic currencies such as Bitcoin are becoming the go-to method for paying online and in retail shops. Easily accept Bitcoin Cash directly or use third-party providers to accept Bitcoin Cash using their platforms and convert all or part of the sale into local fiat currency.
Bitcoin Cash was launched in August 2017, as a direct response to small block sizes on the Bitcoin code. 1MB block sizes were not meeting the demand of the growing community, so a group of dissatisfied crypto enthusiasts decided to create a ‘hard fork’ of the Bitcoin blockchain, with an increased 8MB block size. No one person currently takes credit for the token’s creation; rather it is attributed to a de-centralized group of developers.