20191331 "Information security professionals Introduction" The first six weeks learning summary

20191331 "Information security professionals Introduction" The first six weeks learning summary

Learning content summary

• How to solve the problem Polya
  1. Analyze the problem 2. List the main tasks of the remaining modules 4. 3. Write to restructure and rewrite as necessary
  polya taught me to split a large problem into many small problems, small problems will be resolved one by one, carrying out summary so big the problem is solved. This is also the principle of divide and conquer.
• Simple types and combinations of types of
  simple theory of types (simple type theory), the so-called variable type is a combination of head: has given propositional function of this combination can have value, that is, propositional function in accordance with its purpose entity as a variant divided type. The basic point is the simple theory of types be layered as a variant purpose entities.
  Syntagmatic term relationship is the relationship between a unit and other units of the same sequence, or co-occurrence of a combination of all the ingredients in a relationship must meet some syntactic and semantic conditions, the performance of the code level, and relationships are the same, only to distinguish from the semantic level.
• Complex data structure
  array is a set of variables having a number
  when the program to be processed in the form of a group of same or similar content data array should be used. Not reflect the intrinsic link between the variables, should organize them into a combination of items, put them as an organic whole. This combination is called term structure .
• Finding and sorting algorithms
  
  
• Complexity of the algorithm
  complexity of the algorithm refers to the resource algorithm after writing into an executable program, run the required resources including time and memory resources.
  Usually they have time complexity and the complexity of the space
• Recursive
  procedure calls itself recursively called programming skills. As a kind of recursive algorithm widely used programming languages. A procedure or function calls itself directly or indirectly in a way, it is usually a large, complex problem into a layer similar to the original problem to solve smaller problems in its definition or description, Recursion only requiring less program can describe the problem-solving process is repeated calculation needed, greatly reducing the code size.

• Security Code
  in order to achieve security code that we usually perform information hiding information hiding means for design and determination module, such that the specific information (data or process) contained within a module, other modules do not need this information, it is not accessible of.

  Textbook learning and problem-solving process

• How to sort the problem a variety of methods to achieve
  solutions [ https://www.cnblogs.com/onepixel/articles/7674659.html ]

• Question two information hiding method specific operations
  solutions [ https://baike.baidu.com/item/ information hide ]

  Code debugging and problem solving in the process

  the length of the encryption key and the encryption codes of xor inequality can not be
  solved
  

  Think

• Abstraction is the most powerful tool for people to handle complex transactions.

  Reference material

  [ Https://www.cnblogs.com/onepixel/articles/7674659.html ]
  [ https://baike.baidu.com/item/ information hide ]