Re-entering the password after null means restarting the original password.

Apple Computer displays the password entered as null. This restart password is the original password. After the iPad restarts, the password you need to enter is the numeric password set by the user before. In the phone security lock mode, you can try to enter the password again after null, use someone else's phone to call you, and then the phone will enter the system, and then go into the settings to remove the automatic lock. screen.

When prompted to enter the gmail password, fill in: "null" (Additional note, it is applicable to some machines and has a lot to do with ROM, so the success rate is not guaranteed).

The introduction and composition of passwords are as follows:

Passwords are symbols compiled according to specific rules and used to convert the information between communicating parties into clear and secret. In other words, a cipher is a sequence of symbols that conceals its true content. It is to use a transformation method to convert information represented by a public and standard information code into an information code that cannot be read by others except the communicating parties. This unique information code is a password. ?

Cryptography is a science with a long history. Ciphers were used to deliver secret messages during the wars between ancient Greece and the Persian Empire. In modern and modern wars, codes are indispensable for transmitting intelligence and commanding wars, and they are also inseparable from diplomatic struggles. Passwords are generally used to maintain confidentiality during information communication transmission and storage.

With the development of computers and information technology, cryptography technology has also developed very rapidly, and its application fields have continued to expand. In addition to information encryption, passwords are also used for data information signature and security authentication. In this way, the application of cryptography is no longer limited to serving military and diplomatic struggles, it is also widely used in social and economic activities.

Today's world has seen the trend of socialization and personalization of password applications. For example: cryptography technology can be applied in e-commerce to identify the identity and commercial credit of both parties to online transactions to prevent "hackers" and fraud in online e-commerce; it can be used in value-added tax invoices.

It can prevent counterfeiting and tampering, put an end to all kinds of behaviors that use VAT invoices to steal, leak, evade, and defraud national tax revenue, and greatly facilitate tax inspections; when used in bank check identification, it can greatly reduce The use of fake checks to commit financial fraud is a financial crime; applied in personal mobile communications, it greatly enhances the confidentiality of communication information, etc.

According to Reuters, a batch of documents declassified by the British Security Service showed the world the results of the work of the British intelligence services for the first time. Deciphering the "skirt code" is one of the famous ones.