What is the conversion of data into a ciphertext?

View Discussion

Improve Article

Save Article

Like Article

View Discussion

Improve Article

Save Article

Like Article

There are two primary ways in which a plain text can be modified to obtain cipher text: Substitution Technique and Transposition Technique. 

1. Substitution Technique: 
Substitution technique involves the replacement of the letters by other letters and symbols. In a more straightforward way, the characters of plaintext are replaced, and other substitute characters, numbers and symbols are used at their place. 

Types of Substitution Technique: 

• Caesar Cipher – 
  In this all characters of plain text is replaced by other characters with same pattern. For example, a replaced with D, B replaced with E.
• Mono Alphabetic Cipher – 
  Major disadvantage of caesar cipher is that all elements are substituted with same technique, it make easy for cryptanalyst to crack it. In Mono Alphabetic Cipher, There is no relation between Substitution of characters. Therefore it makes harder for cryptanalyst to crack it. For example, a can be replaced with B-Z, B can be replaced with A, C-Z.
• Homophonic Substitution Cipher – 
  In this technique, one plain text alphabet can map to more than one cipher text alphabet. This is the best substitution technique with maximum security. For example, a can be replaced with D and E.
• Polygram Substitution Cipher – 
  In this rather than replacing one alphabet, block of alphabet is replaced. For example,

• Vigenere Cipher – 
  This technique uses multiple character keys. Each of the keys encrypts one single character. Each character is replaced by a number (A=0, B=1, …Z=25). After all keys are used, they are recycled. For encryption, Formula used : E=(M+K)mod 26

2. Transposition Technique: 
In transposition technique, the identity of the characters remains unchanged, but their positions are changed to create the ciphertext. 

Types of Transpositional Techniques: 

(i) Rail Fence Technique – It uses a simple algorithm:

1. Write down plain text message as sequence of diagonals.
2. Read the plain text written in step 1 as sequence of rows.

(ii) Simple Columnar Transposition Technique – It uses a simple algorithm: 

1. Write the plain text message row by row in predefined columns.
2. Read the message column by column. It can be in any order.
3. Message thus obtained is cipher text message.

Now we can read in any order of columns. Lets read it by 3 -> 2 -> 4 ->1

(iii) Vernam Cipher – It uses a simple algorithm: 

1. Treat each plain text character as a number in the increasing sequence (A=0, B=1, …Z=25).
2. Do the same for each character of the key.
3. Add each number corresponding to plain text alphabet and key.
4. If the sum produced is greater than 26, subtract 26 from it.
5. Translate each number of sum back to alphabet, it gives our ciphertext.

Weakness of each technique, 

In the case of Substitution: 

1. Because it’s based on the substitution of one letter with another based on a translation table. Once the translation table is known, the code is broken.
2. Short words, words with repeated patterns, and common initial and final letters all give clues for guessing the pattern of the encryption.
3. An encryption algorithm must be regular for it to be algorithmic and for cryptographers to be able to remember it. Unfortunately, the regularity gives clues to the cryptanalyst to break a substitution.

In the case of Transposition: 

Just as there are characteristic letter frequencies, there are also characteristic patterns of pairs of adjacent letters, called diagrams (groups of 2 letters) and trigrams (groups of 3 letters). The frequency of appearance of letter groups can be used to match up plaintext letters that have been separated in a ciphertext. 

As in previous weeks, there is some terminology we need to introduce:

Proactively secure confidential data on disks and removable media –

Encryption is the conversion of data into a form, called a cipher text that cannot be easily understood by unauthorized people. Decryption is the process of converting encrypted data back into its original form, so it can be understood.

Mobile computers are quickly emerging as the industry standard for increasing user productivity. However, the portable nature of these devices increases the possibility of loss or theft. Consequent exposure of sensitive data can result in financial loss, legal ramifications, and brand damage.

Disk Encryption provides enterprises with comprehensive, nonstop disk encryption for Microsoft and Apple Mac OS X, enabling quick, cost-effective protection for data on desktops, laptops, and removable media. The encrypted data is continuously safeguarded from unauthorized access, providing strong security for intellectual property, customer and partner data, and corporate brand equity.

Email encryption for desktops and laptops

Email is the most important business communications system in the world, enabling organizations to efficiently interact with customers, clients, and business partners. Yet unprotected email poses a critical risk to an enterprise’s most sensitive data: customer information, financial data, trade secrets, and other proprietary information. Exposure of this information to unauthorized parties can result in financial loss, legal ramifications, and brand damage.

Organizations can minimize the risk of a data breach and comply with partner and regulatory mandates for information security and privacy by encrypting their business sensitive mails.

SearchNetworking

• wireless mesh network (WMN)

  A wireless mesh network (WMN) is a mesh network created through the connection of wireless access point (WAP) nodes installed at ...

• Wi-Fi 7

  Wi-Fi 7 is the pending 802.11be standard under development by IEEE.

• network security

  Network security encompasses all the steps taken to protect the integrity of a computer network and the data within it.

SearchSecurity

• What is the zero-trust security model?

  The zero-trust security model is a cybersecurity approach that denies access to an enterprise's digital resources by default and ...

• RAT (remote access Trojan)

  A RAT (remote access Trojan) is malware an attacker uses to gain full administrative privileges and remote control of a target ...

• supply chain attack

  A supply chain attack is a type of cyber attack that targets organizations by focusing on weaker links in an organization's ...

SearchCIO

• spatial computing

  Spatial computing broadly characterizes the processes and tools used to capture, process and interact with 3D data.

• user experience

  User experience (UX) design is the process and practice used to design and implement a product that will provide positive and ...

• privacy compliance

  Privacy compliance is a company's accordance with established personal information protection guidelines, specifications or ...

SearchHRSoftware

• talent acquisition

  Talent acquisition is the strategic process employers use to analyze their long-term talent needs in the context of business ...

• employee retention

  Employee retention is the organizational goal of keeping productive and talented workers and reducing turnover by fostering a ...

• hybrid work model

  A hybrid work model is a workforce structure that includes employees who work remotely and those who work on site, in a company's...

SearchCustomerExperience