2017 3-4/5 two-day learning REVIEW, 2017 review

2017 3-4/5 two-day learning REVIEW, 2017 review

I'm going to have an interview tomorrow. I 'd like to feel it again. It's estimated that it's an abuse, blue thin ......

April March 4:
Basic Computer Security Technology and principles

The password system (password) consists of five parts:

Message space (m), ciphertext space (c), key space (k), encryption algorithm (E), decryption algorithm (D)

There are two types of passwords: symmetric passwords and non-symmetric passwords. The main difference is whether the keys used by the sender and receiver are the same, kd = ke, or symmetric passwords.

Symmetric passwords have both group passwords and serial passwords: The Key is divided by group encryption.

The group password has five working modes: The Electronic cipher book mode (one-to-one correspondence between ECM, m and c) and the cipher group chain mode (CBC, m and c perform exclusive or operations ); password feedback mode (CFM, rightmost), output feedback mode (OFB, Output c), and count mode (CTR ).

The product password is calculated using a combination of multiple functions. Each f may be the next replacement or replacement.

Several encryption modes in symmetric passwords: DES, IDEA, and ADE.

Encryption modes of asymmetric cryptography: RSA, ElGamal (discrete logarithm), and Elliptic Curve Cryptography (ECC, discrete logarithm of an elliptic curve)

Two integers a and B. If they are equal to the remainder obtained by dividing them by an integer m, a and B are called the same remainder of the Modulo m and recorded as a mod m ), read as a is the same as that of B mode m, or read as a is the same as that of B mode m. For example, 26 Jun 14 (mod 12 ).

 

In general, it is still complicated to understand the encryption process. The concepts of S box and P box also need to be understood for a long time. Haha

 

March 5

C # Let's take a rough look at the iterator, implicit type, Lambda expression, static method, and a small part of LINQ.

I mainly read the iterator writing method, focusing on interface calling and yield usage. I will not write the foreach traversal and other classes.

Public IEnumerator GetEnumerator ()

{

For (int index = 0; index <= arr. Length; index ++)

{

Yield return arr [index];

}

}

 

Read Algorithm forth Edition

I have some understanding of C #, but the book is java, and I can only continue to brush the book. The basic part mainly talks about some library calls and how to use the math library. There is no java on the computer, I will install a compiler later, but I have read some examples, which is quite helpful. I will finish the exercises and Summerize them.

 

Today, linux's zip and unzip operations are not moved ......

But I found that the input method is difficult to use. linux is really cool.

Today, I found some problems with my previous understanding of soft links and hard links. I need to study hard links more !!!