Joke Collection Website - Blessing messages - Many websites need to enter a "verification code". What is the purpose of entering the verification code?

Many websites need to enter a "verification code". What is the purpose of entering the verification code?

Let's talk about a few examples first

There is a new word called "water army", which refers to people who are employed by online public relations companies and use posting and reply as the main means to create momentum for employers on the Internet. For example, if a company launches a new product, in order to expand its influence, it can hire a "network public relations company". The company will convey the task to its members step by step. Members will use some tools to quickly register ID and register accounts of many major forum websites, and also use batch posting tools to post many evaluation posts, and there will be repeated voting ... In short, they will do many insincere things and use huge cluster effects to realize employer brand hype, product marketing, word-of-mouth maintenance, crisis response and so on. In the final analysis, it is an unfair competition.

Tell me more about the password. I don't know the password, but I have to log in to their account. I don't have excellent technology yet, so I can only choose the most helpless "violent cracking"-that is, exhaustive, that is, using machines to run passwords, that is, trying one by one. If 12 letters are still case-sensitive, and there are no social engineering clues about phone number and date of birth, there is no way (unless you run it on a supercomputer). If the 6-digit letter is a simple password, someone will definitely be willing to try it, and it will take a little time at most.

And this is a malicious attack. Websites sometimes encounter malicious attacks from clients, and one of the most common means of attack is identity deception. It refers to writing some code in the client script, and then using its client to log in to the website forum repeatedly; Or the attacker creates an HTML form with the same fields as your registration form or posting form, and then uses "http-post" to transmit data to the server, so that the server can create an account and submit junk data. If the server itself cannot effectively verify and reject this illegal operation, it will seriously consume its system resources, reduce the performance of the server, and even make it crash.

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So the verification code of the page is very useful.

Because the verification code exists in an irregular form in a picture mixed with many disturbing pixels, it is difficult for people to see it, and it is even more difficult for machines to recognize it. It can effectively prevent malicious operations such as batch registration, repeated voting, irrigation reply, and violent cracking. , which plays a vital role in the maintenance of the server!