Network Security Applications

1.What is network & security?

ANSWER
Network is a group of computers where many computers are connected to each other user a server or many are not. As well as security is concern is that no an authorize user can access to your network. We can user firewall to protect network.

2.How do you use RSA for both authentication and secrecy?

ANSWER
RSA is based upon public key/private key concept. For authentication one can encrypt the hash (MD5/SHA) of the data with his private key. This is known as digital signature. And secrecy is achieved by encrypting the data with the public key of the target user. Generally we dont use RSA for encryption because of key size (1024 bits). Rather a symmetric session key (128/256 bit) is established between communicating parties and is used for encryption.

3.How do you do authentication with message digests (MD5)? (Usually MD is used for finding tampering of data)

ANSWER
The unique number will be generated by MD5, if it is tamped with someone, the value will be changed so you know you are tampered.

4.What are digital signatures and smart cards?

ANSWER
Digital signature: Information that is encrypted with an entity private key and is appended to a message to assure the recipient of the authenticity and integrity of the message. The digital signature proves that the message was signed by the entity that owns, or has access to, the private key or shared secret symmetric key.

5.What is Encryption?

ANSWER
In cryptography, encryption is the process of transforming information (referred to as plaintext) using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information (referred to as cipher text).

6.What is Cryptography?

ANSWER
Cryptography is the practice and study of techniques for secure communication in the presence of third parties.

7.What is a key in Cryptography?

ANSWER
A key is a piece of information (a parameter) that determines the functional output of a cryptographic algorithm or cipher. Without a key, the algorithm would produce no useful result. In encryption, a key specifies the particular transformation of plaintext into cipher text, or vice versa during decryption. Keys are also used in other cryptographic algorithms, such as digital signature schemes.

8.What is Key Exchange?

ANSWER
Key exchange (also known as "key establishment") is any method in cryptography by which cryptographic keys are exchanged between users, allowing use of a cryptographic algorithm. If sender and receiver wish to exchange encrypted messages, each must be equipped to encrypt messages to be sent and decrypt messages received.

9.How checksum is used in Network Security?

ANSWER
A checksum or hash sum is a fixed-size datum computed from an arbitrary block of digital data for the purpose of detecting accidental errors that may have been introduced during its transmission or storage. The integrity of the data can be checked at any later time by recomputing the checksum and comparing it with the stored one. If the checksums match, the data were almost certainly not altered (either intentionally or unintentionally).

10.What is Firewall?

ANSWER
A firewall is a device or set of devices designed to permit or deny network transmissions based upon a set of rules and is frequently used to protect networks from unauthorized access while permitting legitimate communications to pass.

11.What is SSL?

ANSWER
The Secure Sockets Layer (SSL) is a commonly-used protocol for managing the security of a message transmission on the Internet

12.What is IP Spoofing?

ANSWER
IP spoofing, also known as IP address fake or a host file hijack, is a hijacking technique in which a cracker masquerades as a trusted host to conceal his identity, spoof a Web site, hijack browsers, or gain access to a network.

13.What is Malware?

ANSWER
Malware, short for malicious software, is software designed to disrupt computer operation, gather sensitive information, or gain unauthorized access to computer systems. While it is sometimes software, it can also appear in the form of script or code. Malware is a general term used to describe any kind of software or code specifically designed to exploit a computer, or the data it contains, without consent. The best-known types of malware, viruses and worms, are known for the manner in which they spread, rather than any other particular behavior. The term computer virus is used for a program that has infected some executable software and, when run, causes the virus to spread to other executables.

14.What is meant by trusted third party (TTP)?

ANSWER
In cryptography, a trusted third party (TTP) is an entity which facilitates interactions between two parties who both trust the third party; The Third Party reviews all critical transaction communications between the parties, based on the ease of creating fraudulent digital content. In TTP models, the relying parties use this trust to secure their own interactions.