There are many types of passwords. Here are a few well-known password types

1. Morse code

Morse code consists of dots (.) and clicks. The two symbols of stroke (-) and click are composed according to the following principles: ?

One point is a basic signal unit, and the length of each stroke is equivalent to the length of 3 points. Within a letter or number, the interval between dots and dashes should be the length of two dots. The space between letters (numbers) is 7 points in length.

2. Caesar shift cipher.

It is the simplest dislocation method, moving the alphabet forward or backward by a few positions.

For example: Plain code table: ABCDEFGHIJKLMNOPQRSTUVWXYZ?

Password table: DEFGHIJKLMNOPQRSTUVWXYZABC, which forms a simple password table. If you want to write frzy (that is, plain text), then compare the above password table The password is

iucb (that is, ciphertext).

You can choose how many digits to shift in the password table, and the number of digits to move is the key.

3. Fence translocation method.

That is, the letters in the message to be transmitted are arranged alternately into upper and lower rows, and then the letters in the lower row are arranged behind the upper row to form a password. ?

Example:

TEOGSDYUTAENNHLNETAMSHVAED?

Solution:

Cut the letters into two lines, as follows

T E?O?G S D?Y U T A?E?N N

H L?N E?T A?M?S H V?A?E?D

Then separate the letters in the second row Put in the first row, you get the following result THE?LONGEST DAY MUST?HAVE AN END.

Extended information:

Password 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 passwords is no longer limited to serving military and diplomatic struggles, it is also widely used in social and economic activities. In today's world, there has been a trend of socialization and personalization of password applications.

For example: cryptography technology can be applied in e-commerce to identify the identities and commercial credit of both parties in online transactions to prevent "hackers" and fraud in online e-commerce.

When used in VAT invoices, it can prevent counterfeiting and tampering, eliminate 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 financial crime of using fake checks to commit financial fraud; when used in personal mobile communications, it can greatly enhance the confidentiality of communication information, etc.

Baidu Encyclopedia--Password