Cryptography 面试题与答案

问题 21. What exactly do you know about SAFER? What is its abbreviation?

SAFER stands for Secure and Fast Encryption Routine and is basically a block chipper.

It has a 64-bit block size and is a byte-oriented algorithm that is widely used. Its encryption and decryption procedures are highly secure and have 10 rounds out of which 6 can be used freely. This technology has wide application in digital payment cards.

问题 22. What is the Fast Data Encipherment Algorithm?

It is basically a cryptosystem that has a 64-bit block size.

Its prime aim is to assure the performance of the software in which it is used. However, due to its insecure approach, it is not so common in the present scenario.

问题 23. What is the difference between Block chippers and Stream Chippers?

Both Block Chippers and Stream Chippers have a similar objective but both operations in a different manner.

Stream Chippers are faster when compared to block.

Block chippers generally operate on the data which is large in size while on the other side, Stream chippers are considered when small units of text are to be considered.

Stream Chipper seems complex in handling the assigned tasks while the Blok chipper is best in performing the same.

In addition to this, block chipper results always error-free and can be trusted for the long run.

问题 24. Name the properties of Interactive proof that are useful in Cryptography according to you?

1. Zero Knowledge
2. Soundness
3. Completeness

问题 25. How you will generate a sequence of binary bits in cryptography?

This can be done with the help of the Linear Feedback Shift Register.

It can perform this task reliably. The register is loaded with some cells that can easily be initialized through a vector which in most cases is nothing but a secret key. At every clocking instant, it is possible to regulate the behavior of the register and thus best outcomes can be assured. It shifts its content to right one by one till every bit is placed on the left side.