Three-wheeled des and triple DES

Ah, this time it's really a real fool. I 've always thought that three or three rounds are the same thing. Today, when I look at the difference analysis, I always think that something is wrong, but I don't know, in the evening, we should summarize the study of differential analysis and find the problem.

The three, eight, and 16 rounds of words are often mentioned in the differential analysis. I am still wondering, not to say that the triple DES efficiency is not very good, but how can it reach 16 again, (In fact, I have always regarded "Wheel" and "heavy" as a matter of code and depressing .)

After detecting that something was wrong, I found another introduction to des from different books. Finally, I found a saying in a book: "Figure 8.3 shows all the 16 rounds of DES (round) encryption/Decryption structure ". This is not clear. The single-weight des is 16 rounds.

So far, I have no idea what the basic unit of DES is. I remember when I was in class, I asked my teacher why des was encrypted over 16 iterations instead of higher. The teacher replied at the time that, because 16 iterations are to be cracked, you can only search for them by means of a poor search. Therefore, Your High iterations only increase the encryption and decryption cost. The reason for this problem lies in the des key. A 56-bit valid key is a defect.

This statement about the use of exhaustive search after 16 iterations is the same as that described in differential analysis overview in the previous article.. This also proves that my previous understanding is wrong.

According to this analysis, the use of this des is still flexible.

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