Cryptography 面试题与答案

问题 11. what are the prime objectives of modern cryptography?

There are four prime objectives and they are:

1. Confidentiality
2. Non-repudiation
3. Authenticity
4. Integrity

问题 12. What do you know about cryptosystems? What is its significance?

These are basically some of the important protocols that assure all the objectives of data encryption have been met.

Regulation of human behavior is also an important module in cryptosystems in which it assures that accounts have been logged off from systems, not in use, passwords that are difficult to guess, maintain the privacy of any information or data that is highly sensitive. 

问题 13. What is the role of Shift Register Cascades in Cryptography?

There are stages when binary bits are needed and this can be done with the help of Linear Feedback Shift Registers.

Registers are required to be connected in such a manner that one register controls the clock for the previous. This type of interconnection is generally regarded as Shift Register Cascades. It shows how the behavior of one register depends on the other.

问题 14. What is the Digital Signature Algorithm?

The digital signature algorithm was implemented for the authentication of data in the year 1994.

It offers quick signature generation and in addition to this, it ensures better verification of information it is dealing with.

It is actually based on computing discrete algorithms and its security actually depends on the size of the key. It can handle key size up to 1024 bits presently.

问题 15. Name the two Signature schemes that are used in Cryptography?

• Special Signature scheme
• Blind Signature Scheme