Why do I need to fill in a verification code to log in to this webpage? Why is the verification code

1）.Captcha is generally to prevent batch registration, and it looks difficult to the human eye, let alone a machine. Two like the post bar is not logged in to post to enter the verification code is probably to prevent the occurrence of large-scale anonymous replies At present, many ** in order to prevent users from using robots to automatically register, log in, and irrigate, all use verification code technology.

The so-called verification code is to generate a string of randomly generated numbers or symbols, add some interfering pixels (to prevent OCR), and the user will recognize the verification code information by the naked eye, enter the form to submit** verification, and only after the verification is successful can a certain function be used.

2）.Generally, the place where the user ID is registered and the major forums require a verification code.

3）.Common captchas.

1. Four-digit number, a random one-digit string, the most original verification code, the verification effect is almost zero. 2. CSDN** user login is in GIF format, which is currently commonly used as a random number ** verification code. **The characters on the ** are more decent, and the verification effect is better than the previous one.

For those who do not have basic graphic iconography knowledge, it is unbreakable! It's a pity that the program that reads it, on the first day that csdn used it, seems to have been published in the forum, which is really pitiful!

3,QQ**User login is in png format,**Random numbers + random capital English letters,The whole composition is a bit flamboyant,Every time you refresh it,Each character will change its position! Sometimes the ** that comes out can't be recognized by the human eye, it's amazing....4. When MS hotmail is applied, it is in bmp format, random number + random capital English letter + random interference pixel + random position.

5, Google's gmail registration is in jpg format, random English letters + random color + random position + random length. 6. Other major forums are in XBM format, and the content is random.

4) Significance: In order to prevent users from using robots to automatically register, log in, and irrigate, they have adopted captcha technology. The so-called verification code is to generate a string of randomly generated numbers or symbols, add some interfering pixels (to prevent OCR), and the user will recognize the verification code information by the naked eye, enter the form to submit** verification, and only after the verification is successful can a certain function be used.

In order to prevent ** from being hacked.

What should I do if the verification code cannot be displayed on the webpage? The specific solution is:

Method 1: 1. Use 360 Security Guard, open it and click [Computer Cleanup];

2. Check all the options and click [Full Cleanup] with your spring hand;

3. After the scan is completed, click [One-click Cleanup], clean up all cache garbage, and restart the browser to see if the verification code can be displayed normally.

Method 2: 1. Right click the stand-alone mouse in the "Start" menu, select the "Control Panel" option;

2. Modify the viewing method of the control panel to "Category", find and click [Uninstall Program] below;

3. Click [Enable or Disable Windows Function] in the upper left corner;

4. Uncheck InternetExplorer, click OK, wait for the uninstallation and restart the computer, then check IE again in the same way, click OK to display the verification code normally after the installation is completed!

Many users need to log in or verify their identity in the process of browsing the web on the computer, and usually ask for a verification code, but sometimes the verification code** cannot be displayed or displayed abnormally, then it will lead to the failure of identity verification. After eliminating the network problem, we can refer to the following methods to start solving the problem.

1. Clean up the cache: The computer has been running for too long, and sometimes there will be too much cache, so you can use the antivirus software on your computer to clean up the cache;

2. Restart the computer: sometimes the computer will self-protect for self-check, and there will be some abnormal situations during self-check, which can be restarted at this time;

3. Upgrade and repair flash: If the flash is not upgraded for too long, the display will be abnormal, and the flash plug-in needs to be upgraded or repaired at this time;

4. Update your browser or use other browsers;

6. It may be caused by a computer virus, you can use antivirus software to kill and restart the computer.

Hello, I am glad to serve you and give you the following answers: Causes: 1. The user's login information may be stolen or subject to other forms of attacks, such as software vulnerability attacks, brute-force attacks, etc.

2. The security of ** is insufficient, and no effective security protection measures are taken to prevent user login information from being stolen. Solution: 1. Adopt a two-factor authentication mechanism, in addition to using a regular username and password, in addition to using a regular username and password, the user is also required to enter a dynamic verification code to ensure that the user's identity is true and valid.

2. Regularly test the security of the first class, find vulnerabilities in time, and repair Qiaoying in time, so as to prevent the user's login information from being stolen. 3. Install a firewall, restrict access to external networks, and regularly update firewall rules to effectively prevent attackers from entering. 4. Establish security logs, record the security status of the first class, check the logs regularly, and detect attacks in time.

5. Adopt security protocols, such as SSL protocol, to protect the user's login information from being stolen.