What is cybercrime? what is Data tempering? all concept

Cybercrimes

What is cybercrime?

Cybercrime is a criminal activity that either targets or uses a computer, a computer network, or a networked device.

Most, but not all, cybercrime is committed by cybercriminals or hackers who want to make money. Cybercrime is carried out by individuals or organizations.

Some cybercriminals are organized, use advanced techniques, and are highly technically skilled. Others are novice hackers.

Rarely, cybercrime aims to damage computers for reasons other than profit. These could be political or personal.

Types of cybercrime

Here are some specific examples of the different types of cybercrime:

·        Email and internet fraud.

·        Identity fraud (where personal information is stolen and used).

·        Theft of financial or card payment data.

·        Theft and sale of corporate data.

·        Cyberextortion (demanding money to prevent a threatened attack).

·        Ransomware attacks (a type of cyberextortion).

·        Cryptojacking (where hackers mine cryptocurrency using resources they do not own).

·        Cyberespionage (where hackers access government or company data).

Most cybercrime falls under two main categories:

·        Criminal activity that targets

·        Criminal activity that uses computers to commit other crimes.

 

How to protect yourself against cybercrime

·        So, now you understand the threat cybercrime represents, what are the best ways to protect your computer and your personal data? Here are our top tips:

·        Keep software and operating system updated

Keeping your software and operating system up to date ensures that you benefit from the latest security patches to protect your computer.

·        Use anti-virus software and keep it updated

Using anti-virus or a comprehensive internet security solution like Kaspersky Total Security is a smart way to protect your system from attacks.

·        Anti-virus software allows you to scan, detect and remove threats before they become a problem. Having this protection in place helps to protect your computer and your data from cybercrime, giving you peace of mind.

·        If you use anti-virus software, make sure you keep it updated to get the best level of protection.

·        Use strong passwords

·        Be sure to use strong passwords that people will not guess and do not record them anywhere. Or use a reputable password manager to generate strong passwords randomly to make this easier.

·        Never open attachments in spam emails

·        A classic way that computers get infected by malware attacks and other forms of cybercrime is via email attachments in spam emails. Never open an attachment from a sender you do not know.

·        Do not click on links in spam emails or untrusted websites

·        Another way people become victims of cybercrime is by clicking on links in spam emails or other messages, or unfamiliar websites. Avoid doing this to stay safe online.

·        Do not give out personal information unless secure

·        Never give out personal data over the phone or via email unless you are completely sure the line or email is secure. Make certain that you are speaking to the person you think you are. 

·        Contact companies directly about suspicious requests

·        If you get asked for data from a company that has called you, hang up. Call them back using the number on their official website to ensure you are speaking to them and not a cybercriminal. 

Data Tampering Definition

Data tampering is the act of deliberately modifying (destroying, manipulating, or editing) data through unauthorized channels. Data exists in two states: in transit or at rest. In both instances, data could be intercepted and tampered with. Digital communications are all about data transmission.

Data tampering Prevention

Data tampering is all about successful illicit system intrusion. So, the first line of defense is handling the 'getting in' part. However, there are other areas of system vulnerabilities that are also addressed. Let's check these out one at a time:

1. Firewalls

Important files, databases, programs, and applications have to be locked down behind a firewall in parallel with operating systems/platform security. A firewall is an electronic barrier to a system and its programs. It may be hardware or software designed for network security and uses various preset criteria to control incoming and outgoing traffic. Controlling network traffic is the first line of defense in preventing unauthorized system access.

Enforce Encryption for Data-at-Rest and Data-in-Transit

Unprotected data, whether at rest or in transit, leave organizations vulnerable to data tampering and other cyberattacks. One of the most effective ways to protect data-at-rest and -in-transit is encryption.

Simply put, data encryption is the process of translating data from one form into another that unauthorized users cannot decrypt.

Copy-on-Write File Systems

Copy-on-write, often referred to as COW, is a concept used to maintain instant snapshots on database servers. It can also help with data tampering prevention.

Each time a database is modified, delta snapshots are taken. Security teams can detect data tampering by monitoring snapshots and checking for unexpected file system snapshots.

Many database applications and operating systems (such as Linux, Unix) come with a built-in snapshot feature. This makes it easy for enterprises to integrate COW or any other similar technology and stay updated about their database modifications. Data Integrity using HMACs

Hash-based message authentication code (HMAC) is a type of message authentication code (MAC) that consists of a cryptographic hash function and a secret cryptographic key.

Basically, an HMAC is a way of signing a message/file so that if the data has tampered with, it is very easy to detect, and then you know not to trust the tampered data.

File Integrity Monitoring (FIM)

File integrity monitoring is a powerful security technique to secure business data and IT infrastructure against both known and unknown threats. FIM is the process of monitoring files to check if any changes have been made.

How does this technology help with data tampering prevention?

It assesses system files and generates a cryptographic checksum as a baseline. Then, the FIM repeatedly recalculates the checksum of the same resources, compares it to the baseline, and if it detects changes, it generates a security alert.

 

WORM systems (Write Once Read Many)

Write once read many (WORM) systems refers to a storage technology where data, once written, cannot be overwritten or modified. This technology has long been used for archival purposes of large enterprises and government agencies.

WORM systems offer a long-term storage strategy that ensures users cannot accidentally or intentionally erase or modify data. This technology provides virtual protection against the erasure of data.

Compromising data on WORM systems is difficult at best, but still possible if an expert with a high degree of technical knowledge has unrestricted access to the deepest levels of the operating system and gains access to the WORM drives.

ENCRYPTION MEANING

Encryption is the process of translating data into a secret format so that only authorized parties can understand the information. Plain text, or readable data that is not encrypted, is converted into ciphertext, or scrambled data that is unreadable. Encryption takes readable data and alters it so it appears random. This is done to protect and secure the confidentiality of data transmitted through a network.

To read an encrypted file, the recipient must have access to a secret key or password that enables them to translate the information back to its original form. This process is called decryption.

TYPES OF ENCRYPTION

There are two main types of encryption: Asymmetric (also known as public-key cryptography) and symmetric. The biggest difference between the two is that symmetric encryption uses one key for both encryption and decryption, and asymmetric encryption uses a public key for encryption and a private key for decryption. Symmetric encryption is the simplest and most-used technique. While asymmetric encryption takes longer to execute because of the complex logic involved, it’s a better choice from a security standpoint

EXAMPLES OF ENCRYPTION

·        Data Encryption Standard (DES): DES is a low-level encryption standard that was established by the United States government in 1977. DES uses a 56-bit key and uses the block cipher method, which breaks text into 64-bit blocks and encrypts them. Because of technological advances, DES is relatively obsolete for protecting sensitive data.

·        Triple DES: Triple DES runs DES encryption three times. It encrypts, decrypts, then once again encrypt data. It strengthens the original DES standard.

·        RSA algorithm: RSA stands for Rivest, Shamir, and Adelman the inventors of the technique. The algorithm is based on the assumption that there is no efficient way to factor in very large numbers. Deducing an RSA key, therefore, requires an extraordinary amount of computer processing power and time.

·        Advanced Encryption Standard (AES): As of 2002, AES is the United States government standard, replacing DES. It works at multiple network layers simultaneously and is used worldwide

 

TYPES OF ENCRYPTION

There are two types of encryptions: asymmetric and symmetric.

Asymmetric Encryption

In public key (asymmetric) encryption, two mathematically-related keys are used: one to encrypt the message and the other to decrypt it. These two keys combine to form a key pair. Asymmetric encryption provides both data encryption and validation of the communicating parties’ identities and is considered more secure than symmetric encryption, but is computationally slower.

A public-key encryption scheme has six major parts:

1. Plaintext – This is the text message to which an algorithm is applied.

b.     Encryption Algorithm – It performs mathematical operations to conduct substitutions and transformations to the plaintext.

c.     Public and Private Keys – This is a pair of keys where one is used for encryption and the other for decryption.

d.     Cipher text – This is the encrypted or scrambled message produced by applying the algorithm to the plaintext message using key.

e.     Decryption Algorithm – This algorithm generates the ciphertext and the matching key to producing the plaintext.

Symmetric Encryption

Private Key encryption (Symmetric), also referred to as conventional or single-key encryption is based on a secret key that is shared by both communicating parties. It enquires all parties that are communicating to share a common key. The sending party uses the secret key as part of the mathematical operation to encrypt (or encipher) plain text to ciphertext. The receiving party uses the same secret key to decrypt (or decipher) the ciphertext to plain text.

Examples of symmetric encryption schemes are the RSA RC4 algorithm (which provides the basis for Microsoft Point-to-Point Encryption (MPPE), Data Encryption Standard (DES), the International Data Encryption Algorithm (IDEA), and the Skipjack encryption technology proposed by the United States government (and implemented in the Clipper chip).

An encryption scheme has five major parts:

1. Plaintext – This is the text message to which an algorithm is applied.

2.     Encryption Algorithm – I performs mathematical operations to conduct substitutions and transformations to the plaintext.

3.     Secret Key – This is the input for the algorithm as the key dictates the encrypted outcome.

4.     Ciphertext -This is the encrypted or scrambled message produced by applying the algorithm to the plaintext message using the secret key.

5.     Decryption Algorithm – This is the encryption algorithm in reverse. It uses the ciphertext, and the secret key to derive the plaintext message.

ENCRYPTION PROCESS

§  The process of encryption begins by converting the text to a pre-hash code. This code is generated using a mathematical formula.

§  This pre-hash code is encrypted by the software using the sender’s private key.

§  The private key would be generated using the algorithm used by the software.

§  The encrypted pre-hash code and the message are encrypted again using the sender’s private key.

§  The next step is for the sender of the message to retrieve the public key of the person this information is intended for.

§  The sender encrypts the secret key with the recipient’s public key, so only the recipient can decrypt it with his/her private key, thus concluding the encryption process.

CRYPTOGRAM

the cryptogram is a type of puzzle that consists of a short piece of encrypted text.Generally, the cipher used to encrypt the text is simple enough that the cryptogram can be solved by hand. Substitution ciphers where each letter is replaced by a different letter or number are frequently used. To solve the puzzle, one must recover the original lettering. Though once used in more serious applications, they are now mainly printed for entertainment in newspapers and magazines.

Cryptography

 

Cryptography is a method of protecting information and communications through the use of codes, so that only those for whom the information is intended can read and process it. The prefix "crypt-" means "hidden" or "vault" -- and the suffix "-graphy" stands for "writing."

Modern cryptography concerns itself with the following four objectives:

1.     Confidentiality: the information cannot be understood by anyone for whom it was unintended

2.     Integrity: the information cannot be altered in storage or transit between sender and intended receiver without the alteration being detected

3.     Non-repudiation: the creator/sender of the information cannot deny at a later stage his or her intentions in the creation or transmission of the information

4.     Authentication: the sender and receiver can confirm each other's identity and the origin/destination of the information

CRYPTANALYST

A cryptanalyst develops mathematical methods and codes that protect data from computer hackers. This involves the decryption of a cipher text into plain text in order to transmit a message over insecure channels.

WHAT CRPTANALYST DO?

A cryptanalyst understands how to decipher secret codes and write codes that cannot be cracked by hackers. These individuals protect the privacy of organizations by supervising the online security of data systems. They also assess and decode secret messages and coding systems for government agencies, police agencies, and the military.

Government agencies and companies hire cryptanalysts to ensure their networks are secure, and that sensitive data transmitted through their computer networks are encrypted. This ensures that organizations and their clients' sensitive data cannot be accessed by hackers.

A.   Cryptography is the science and art of designing algorithms for secret communication
B. Cryptanalysis is the study of "breaking" cryptographic designs
C. Cryptology = A + B

Cryptanalysts have distinct personalities. They tend to be investigative individuals, which means they’re intellectual, introspective, and inquisitive.

DIFFERENCE BETWEEN CRPTOGRAPHY & ENCRYPTION

The basis of comparison	Cryptography	Encryption
Definition	Study of techniques like encryption and decryption.	A process of encoding a message.
Nature	Cryptography is a field of study.	Encryption is more of a mathematical operation.
Basis	Based on mathematics and algorithms concepts.	Concepts like a cipher, ciphertext, key are used
Utilization	Digital signature and security-related algorithms.	Facilitate secret communication.
Category	Symmetric and public key Cryptography.	Symmetric and Public key schemes, just like Cryptography.
Message verification	Cryptography encompasses Encryption, including other techniques.	Encryption being a subset of Cryptography using an algorithm – cipher.

Cryptography involves various techniques and technologies, including algorithms, mathematics, information theories, transmission, encryption etc. Encryption is one such technique of Cryptography. A standalone, Encryption process can confidentially provide the message, but at the same time, other techniques and strategies are required to provide the integrity and authenticity of a message. So, in a nutshell, a successful scheme should provide data integrity, authentication, and non-repudiation, which is what Cryptography provides.

CIPHER

In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure.  In common parlance, "cipher" is synonymous with "code", as they are both a set of steps that encrypt a message; however, the concepts are distinct in cryptography, especially classical cryptography.

1. Caesar Cipher

In Caesar cipher, the set of plain text characters is replaced by any other character, symbols or numbers. It is a very weak technique of hiding text. In Caesar’s cipher, each alphabet in the message is replaced by three places down. Let’s see one example. The plain text is EDUCBA. As a Caesar cipher, each alphabet is replaced by three-place down so that E will replace by H, D will replace by G, U will replace by X, C will replace by F, B will replace by E, and A will replace by D. So here the plain text is EDUC BA and ciphertext Is HGXFED.

 

2. Monoalphabetic Cipher

As Caesar cipher and a modified version of Caesar cipher is easy to break, monoalphabetic cipher comes into the picture. In monoalphabetic, each alphabet in plain text can be replaced by any other alphabet except the original alphabet. That is, A can be replaced by any other alphabet from B to Z. B can be replaced by A or C to Z. C can be replaced by A, B, and D to z, etc. Mono alphabetic cipher causes difficulty to crack the message as there are random substitutions and a large number of permutation and combination are available.

3. Homophonic Substitution Cipher

A homophonic substitution cipher is similar to a monoalphabetic cipher; the only difference is in monoalphabetic, we replace the alphabet with any other random alphabet except the original alphabet wherein homophonic substitution cipher, the alphabet is replaced by fixed alphabet or set of alphabet. The substitution alphabet is replaced with te fixed. For example, replace A with x, E with B, S with A, etc. or replace A with E, x or L, B with T, A, Z, etc.

4. Polygram Substitution Cipher

In polygram substation cipher, rather than replacing each alphabet with another, the alphabets’ Block is replaced with another block of alphabets. Replace EDUCBA with XYQLAB. In this case, EDUCBA will replace with XYQLAB, but EDU can be replaced with another set of the block, let’s assume EDU will replace with LOD. In this type of ciphers, plain text replacement is done through the block by block rather than character by character.

5. Polyalphabetic Substitution Cipher

Polyalphabetic Cipher is also known as Vigenere Cipher, which Leon Battista Alberti invents. In Polyalphabetic Substitution, Cipher is a method of encrypting alphabetic texts. It uses multiple substitution alphabets for encryption. Vigener square or Vigenere table is used to encrypt the text. The table contains 26 alphabets written in different rows; each alphabet is cyclically shifted to the left according to the previous alphabet, equivalent to the 26 possible Caesar Ciphers. The cipher uses a different alphabet from one of the rows at various points in the encryption process.

1  a  b  c  d  e               PLAIN TEXT

2  b  c d  e  f                   DAD

3 c  d  e  f  g         SECRET KEY  54321

4 d  e  f  g  h                   HDF

5 e  f  g  h  i

6. Playfair Cipher

Playfair cipher is also called Playfair square. It is a cryptographic technique that is used o encrypt the data. The Playfair cipher process is as follows:

• Creation and population of the matrix.
• Encryption process.

7. Hill Cipher

Hill cipher works on multiple alphabets at the same time. Hill cipher works as follows:

1.  Assign the number to each alphabet in plain text. A = 0, B= 1….z = 25
2. Organize the plain text message as a matrix of numbers based on the above step in number format. The resultant matrix is called a plain text matrix.
3. Multiply the plain text matrix with a randomly chosen key. Note that the key matrix must be the size of n*n where n stands for the number of rows in a plain text matrix.
4. Multiply both the matrix, i.e. step 2 and step 3.
5. Calculate the mod 26 value of the above matrix, i.e. matrix results in step 4.
6. Now translate the numbers to alphabets i.e. 0 =A, 1 =B, etc.
7. The result of step 6 becomes our ciphertext.

DECIPHER

to make out the meaning of (poor or partially obliterated writing, etc.)

to discover the meaning of (anything obscure or difficult to trace or understand)

Decipher means translate from code, or more generally, figure out. If you can’t decipher your teacher's writing, it means you can't read it. You might feel like you're being asked to decipher a code.

                JUMBLING

 word jumble is a word puzzle game that presents the player with a bunch of mixed up letters and requires them to unscramble the letters to find the hidden word. ... An example of a simple word jumble might be “d-a-r-h-c-l-e-t-a.” If you found “cathedral,” nice work!

CRYPTOSYSTEM

In cryptography, a cryptosystem is a suite of cryptographic algorithms needed to implement a particular security service, most commonly for achieving confidentiality (encryption).

Typically, a cryptosystem consists of three algorithms: one for key generation, one for encryption, and one for decryption.

DES

The DES (Data Encryption Standard) algorithm is a symmetric-key block cipher created in the early 1970s by an IBM team and adopted by the National Institute of Standards and Technology (NIST). The algorithm takes the plain text in 64-bit blocks and converts them into ciphertext using 48-bit keys.

Data Encryption Standard (DES), an early data encryption standard endorsed by the U.S. National Bureau of Standards (NBS; now the National Institute of Standards and Technology). It was phased out at the start of the 21st century by a more secure encryption standard, known as the Advanced Encryption Standard (AES), which was better suited for securing commercial transactions over the Internet.