Cyber Security Interview Questions

Following is a list of main advantages of cyber security :

The **Open Systems Interconnection (OSI)** model is a reference model that describes how applications interact with each other over a computer network. It has seven layers; they are as shown below :

Cryptography is the study of encrypting and decrypting data to prevent unauthorized access. The ciphertext should be known by both the sender and the recipient. With the advancement of modern data security, we can now change our data such that only the intended recipient can understand it.

Cryptography allows for the secure transmission of digital data between willing parties. It is used to safeguard company secrets, secure classified information, and sensitive information from fraudulent activity, among other things. Crypto means hidden and graph means writing.

Encryption is a fundamental component of cryptography, as it jumbles up data using various algorithms. Data encryption is the method of undoing the work done by encrypting data so that it can be read again. Cryptography is dependent on both of these methods.

Cryptography is classified into two categories based on the types of keys and encryption algorithms :

Let’s take a closer look at each type.

For example, Bob wants to send an encrypted message to Alice, and they agree to encrypt his message using public-key encryption. The receiver initiates public key encryption to encrypt the sender’s message. The receiver, not the sender, initiates the public key method to encrypt the sender’s message. Everyone has access to the public key. The receiver, Alice, is the only one who has access to the private key. The following is how it works :

A digital signature is equivalent to a handwritten signature. It is an electronic verification of the sender. Digital signatures are commonly used for software distribution, financial transactions. The digital signature serves three purposes :

The functioning of cryptography revolves around cryptographic algorithms. Cryptographic algorithms or ciphers are mathematical functions that are combined with keys, such as phrase, digit, word, etc., to encrypt text. The effectiveness depends on the strength of the cryptographic algorithms and the secrecy level of the key.

Multiple complex combinations of algorithms and keys boost the effectiveness of a cryptosystem.

Some major techniques of Cryptography are listed below :

RSA is an asymmetric cryptographic algorithm. RSA Algorithm that works on a block cipher concept that converts plain text into ciphertext and vice versa at the receiver side. If the public key of User

**A**

is used for encryption, we have to use the private key of the same user for decryption.**p**

and **q**

where **p**

not equal to **q**

.**Calculate n= p*q and z=(p-1)*(q-1)**

**ed-1**

) is exactly divisible by 2.**n**

, **d**

, and **e**

**c=m pow(e) mod n**

**(where m is plain text and c is ciphertext)**

**m= c pow(d) mod n**

**e, n**

) is the public key used for encryption. (**d, n**

) is the private key used for decryptionThe **RSA** algorithm has the drawback of being quite inefficient in cases in which large volumes of data must be authenticated by the same virtual machine. A foreign entity must substantiate the dependability of authentication tokens. Data is routed through middlemen, who may corrupt with the cryptosystem.