Hill encrypted joke

Production cost calculation: In social production management, it is often necessary to make statistics, processing and analysis on a large amount of data generated in the production process, so as to understand and monitor the production process, and then manage and regulate the production to ensure the normal and stable production and achieve the best economic benefits. However, the original data are often complicated, and some methods are needed to process the data and generate direct and clear results. The introduction of matrix in calculation can handle a large number of data, which is relatively simple and fast.

2. Population mobility?

Assume that there are 400,000 people engaged in agriculture, industry and commerce in a small and medium-sized city and suburban township, and assume that the total number remains unchanged for several years. Social surveys show that:

(1) Of the 400,000 employed people, about 250,000 are currently engaged in agriculture.

People are engaged in industry, and 50 thousand people are engaged in business; ?

(2) Among farmers, about 65,438+00% turn to work and 65,438+00% turn to business every year; (3) About 65,438+00% of migrant workers turn to agriculture and 20% turn to commerce every year; (4) Among business people, about 65,438+00% turned to agriculture and 20% turned to work.

Now I want to predict the number of people engaged in various industries in one or two years, and the development trend of the total number of people engaged in various industries after many years.

3. Use matrix to encode Hill code?

Cryptography plays an extremely important role in economy and military affairs. In cryptography, information code is called cipher, text information that has not been converted into cipher is called plaintext, and information represented by cipher is called ciphertext. The process of converting plaintext into ciphertext is called encryption, and vice versa. Now cryptography involves a lot of advanced mathematical knowledge. ?

1929, Hill encrypted the transmitted information by matrix theory, and put forward Hill's encryption algorithm, which played an important role in the history of cryptography. Here is the basic idea of this algorithm.

4. Computer graphics conversion?

The coordinates of the midpoint in the computer are expressed by homogeneous vector coordinates, that is, n+ 1 dimension vector is expressed by n-dimension vector. For example, point A(x, y, z) is expressed as a (x, y, z, 1) in homogeneous vector coordinates. ?

Application of matrix inversion

1. Encrypted secure communication model?

Secure communication is a very important topic in the new era. More and more researchers have done a lot of work for it and put forward many more effective secure communication models. Among them, the secure communication model based on encryption technology is the most basic and dynamic model. ?

The sender uses an algorithm to encrypt and convert plaintext data into ciphertext data and then sends it to the receiver, and the receiver can use the corresponding algorithm to decrypt and convert ciphertext data into plaintext data.

It can be seen from the model that whether an encryption technology is effective depends on whether the ciphertext can be restored to plaintext. With the matrix equation CAB? , where b is the unknown matrix. We know that if A is an invertible matrix, then the equation

There is a unique solution-1BAC? , where-1A is the inverse matrix of a, so the invertible matrix can be effectively applied to encryption technology.

2. Find the power of the square matrix

3. Solve the matrix equation