2019-2020-1 20175308 "Information security system design basis" the second week of learning summary

2019-2020-1 20175308 "Information security system design basis" the second week of learning summary

Teaching materials summary

First, the scale and its conversion

(1) constituting the hexadecimal

• With our most familiar decimal, for example, is composed of decimal numbers

, I.e. each bit decimal value by bit for your weight multiplied.

• Referring to a decimal number, the rest of the way to form each binary numbers are in fact the case, the only difference is that base-digit rights

  (2) Conversion between hexadecimal

  Conversion between decimal and hexadecimal k - k modulo addition method

  That is, each part is divided by the integer k, the number of digital rights for the remainder, and continue dividing the quotient k, and the remainder is the number on the right a bit, this step has been sustained until the quotient is zero till, finally reading time, starting from the last remainder, up to the front of a remainder.
  Note ⚠️: the last one is repeated except k obtained, so the actual number of digits as a result of the highest level

  Other mutual conversion between hex - indirect conversion

  We are most likely to complete the conversion between various binary and decimal, so the methods we can use indirect conversion, usually first converted to decimal (in many cases will choose binary ), then to the purpose of binary transformation.
  

Second, the concept of position

Third, the context information bits + =

Fourth, the storage of information

After running the code

Code debugging and problem solving in the process

The learning content more focused on the concept, not a particularly large number of codes, and did not encounter any problems in the learning process.
Here is the code run shot:

Code hosting

Sentiment

The study is mainly theoretical study on the nature, content and not too much practice. In fact, relevant content before other subjects in the study had some contact, but this study is relatively more systematic, more to explain for the computer system, the relatively new angle, for some details not previously learned has also been supplemented