What is the significance of CAPTCHAs? What does a captcha refer to?

Effectively prevent this problem from constantly logging in to a specific registered user with a specific program brute force crack, in fact, using a verification code is now a common way (such as China Merchants Bank's online personal banking, Tencent's QQ community), we use a relatively simple way to achieve this function. Although it is a little more troublesome to log in, this feature is still necessary and important for the community. However, we still remind everyone to protect their passwords, try to use more than 6 digits of passwords that are mixed with numbers, letters, and symbols, and do not use simple passwords such as 1234 or passwords that are the same or similar to your username.

There is also a verification code when registering to publish an article, just to prevent people from using a keygen, unlimited automatic registration.

It's necessary, but it's really annoying!

My verification code is an SMS verification code.

The verification code is a string of randomly generated numbers or symbols, and a ** is generally used to prevent batch registration. SMS verification code is an effective verification code system by sending verification codes to mobile phones. Whether it is large**especially shopping**, it provides a mobile phone SMS verification code function, which can ensure the safety of shopping more accurately and safely, and verify the correctness of users.

**There is a string of numbers in the text message sent to your mobile phone, that is, the verification code, which is generally used to register or bind the mobile phone. Some verification code access providers provide SMS verification code service, each ** sends a request to the access provider's server through the interface, and the server sends random numbers or letters to the mobile phone, and the access provider's server uniformly verifies the verification code.

The common verification code is a four-digit number, a random one-digit string, the most original verification code, the verification effect is almost zero, the user login is in GIF format, the current commonly used random number ** verification code, the characters on the ** are more decent, and the verification effect is better.

A CAPTCHA is a set of strings of letters, numbers, or symbols that are used to identify and confirm a user. It is often used in the verification process of registration, login, password recovery, etc., to prevent malicious attacks, brute force attacks, and other behaviors.

Refers to a person's captcha.

Captcha, as the name suggests, is used to verify identity. There are behavioral captchas on the network, such as 12306, which illuminates something among many **; There is also a complete **, in which the missing part needs to be dragged and dropped by the user; There is also a ** with objects with different angles, which need to be clicked by the user to achieve all the positive directions. The existence of behavioral verification codes is to prove that the user is being operated by a real person, and not by a network virus or a user disguised by the program.

In order to further prevent corporate coupons from being struck by fake users, or corporate SMS verification codes from being attacked and costing in vain.

The other is SMS verification code. Most of the SMS verification codes are used for user identity verification in the user registration amount, login, payment and other links, and the account password login parallel, which is a rigid need for the operation of the enterprise membership system.

Prevent malware from logging in automatically.

The main function of the verification code is to detect whether you are a real person or a robot, and the SMS verification code not only detects whether you are a person, but also verifies whether you are the account holder.

By the way, there are some types of captchas.

1) SMS verification code.

The most we encounter should be the SMS verification code, when logging in to the registered account, retrieving the password, binding the mobile phone, and mobile banking transfer, we must use the SMS verification code verification. The SMS verification code is more to ensure that it is operated by the person. At present, the relatively large SMS verification code in China are:

Chuanglan 253, Ali Big Fish, Montnets, etc.

1. Captcha is a public automatic program that distinguishes people from computers. Due to the rampant network viruses, hackers, and number theft on the Internet a few years ago, verification codes were widely implemented.

2. The use of verification codes can effectively prevent hackers from using specific programs to continuously brute force attacks and crack a specific account, and solve many network order problems such as ticket swiping, page swiping, forum flooding, password cracking, and malicious registration.