The world became a smaller place with the advent of the Internet but it also meant compromising data privacy. We needed assurance that our personal or sensitive data reached only authorized readers. In the early 1970s, IBM developed DES. What is DES? Data Encryption Standard is a method of encrypting and decrypting data using a symmetric key to keep confidential or classified information safe from hackers. It is the first form of cyber security.

Explanation of What is DES
Pic Courtesy: GeeksforGeeks

The National Institute of Standards and Technology (NIST) accepted the DES. It came into use in 1977 and it officially retired in 2005. What is DES in simple language?


It is an algorithm that divides plain text into 64-bit smaller blocks and converts them into encrypted text or ciphertext using 48-bit keys. A Symmetric cryptography key decodes this ciphertext. This means that the same key encrypts and decrypts text.

Origin of DES

The US Government had called for data security. In the 1970s, a team from IBM developed a data encryption system with some help from the National Security Association. It was submitted to the National Institute of Standards and Technology (NIST), USA. In November 1976 NIST adopted it. DES was now a Federal Information Processing Standard (FIPS) PUB 46. It is for use on unclassified data. It renewed as the standard for data encryption in 1983, 1988, 1993, and 1999.

What is DES algorithm?

  • Groups of 64-bit blocks of text form from the data input.
  • A key encodes each block into 64-bit ciphertext. This happens through permutation and substitution. DES uses LUCIFER, a block cipher developed by Horst Feistel.
  • An initial permutation forms two parts of 32-bit of each block, Left plain text (LPT) and Right plain text (RPT).
  •  Every LPT and RPT encrypts 16 times.
  •  Each round of encryption generates 16 different 48-bit subkeys.
  •  LPT and RPT rejoin. The algorithm performs a final permutation. This results in the 64-bit ciphertext.
  • The algorithm generates a 64-bit key for encrypting and decrypting the text. Parity checks take place on 8 bits. So the actual length of the key is only 56 bits.
  • A reverse process decodes the text using the same key.
What is DES?
Pic courtesy: Wikipedia

Security and safety

The biggest drawback of DES is the 56-bit key. Advanced technologies made it easier to crack the keys and subjected DES to brute force attacks. The 56-bit key was too small and susceptible to cracking. In July 1998 Electronic Frontier Foundation (EFF) cracked the 56-bit key with the “Deepcrack”, an EFFDES cracker machine.  DES cracking machines are capable of searching all the keys in approximately seven hours. The chips can encode and decode over a million DES operations in one second. Differential cryptanalysis (DC), Linear cryptanalysis (LC), and Davis’ attack can break the full 16 rounds of DES easily. In 2005 NIST officially discontinued it.

Triple DES and AES

To counter the attacks, an improved DES called Triple DES came into force in 1997. It uses the same DES core. There are three passes with three different keys. NIST decided to use it only as a temporary solution. In 2002, NIST introduced an advanced and less susceptible algorithm. Advanced Encryption Standard (AES) superseded DES as the accepted cipher system. The US government will use Triple DES for sensitive information till 2030. AES is a 128-bit block encoder with a key size of 128 bits, 192 bits, or 256 bits. The AES algorithm has yet to be cracked.

What is DES’ Modus Operandi?

One should choose the right security provider for encrypting. The selection is based on the language used like C, Java, Python, MATLAB, etc. Create a key on your own or through the Key Generator. Lastly, check for errors in encryption using testing procedures.

There are five different methods of encrypting and decrypting in DES.

  1. Electronic Codebook (ECB): The data forms blocks of 64 bits. Each block of 64 bits is coded and decoded individually into ciphertext.
  2. Cipher Block Chaining (CBC): This is an improvement on the ECB since the ECB had some security issues. It uses an Initialization Vector. Every 64-bit block of text is numerically combined with the previously encoded block to encrypt itself. One error in any block can corrupt the decoding.
  3. Cipher Feedback (CFB): In this case, the output of the previously encrypted block numerically combines with the present text block to turn it into a ciphertext block. This does not show the plaintext patterns.
  4. Output Feedback (OFB): The difference between OFB and CFB is that in OFB the encryption algorithm input for the current block of plain text is the subkey or the output from the previous ciphertext. The errors in the previous encryption will not affect this block encryption.
  5. Counter (CTR): Cipertext blocks are created when an encrypted counter XORed’s plaintext. The counter adds for each succeeding block.
What is DES?

What is DES used for?

The key in DES is easy to crack. This resulted in the discontinuation of the data encryption standard. It is the first encryption standard. DES is the base for all future encryption algorithms. To comprehend new encryption methods, a good understanding of the original algorithm is helpful. Triple DES evolved from this algorithm. It is a legacy encryption algorithm.

DES Algorithm in Education

This algorithm is the foundation for all the later encryption algorithms in cryptography. In cryptanalysis, students learn SDEC or simplified Data Encryption Standard. The structure and properties remain similar to those of DES but are simplified. Encryption and decryption are easier and penned by hand.

Cryptography and cyber security are very important in today’s world. The field is vast and the demand insatiated. A candidate can learn and update oneself in this field by pursuing courses on related topics. Students can go in for programming, learning coding and decoding, and courses in cyber security.

Courses at Henry Harvin:

Henry Harvin provides training and advisory services worldwide. It is one of the top 500 Global Edtech companies. Henry Harvin has more than 800 courses on varied subjects. The students can avail of data science courses which have a diploma, BSc, post-graduation, master’s, and programming languages like Python to choose from. Henry Harvin runs basic to master’s courses in cybersecurity. The Ethical Hacking course and Computer Hacking Forensic Investigator course are in demand.


Data Encryption Standards is officially out of commission. Yet, it is important and experts talk about it. Data privacy and safety are major requirements the world over. Encryption is important to every business today. In this day of cutthroat competition and hacking of systems, the protection of confidential data is of utmost priority. Converting data into cipher text and an untraversable encryption key to protect it is the need of the day. DES has shown the path for improved algorithms for information security.


1. Is Encryption and Decryption part of Cryptography?

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A. Cryptography is the process of coding data and has been used since time immemorial. Information is encrypted and can only be decrypted by the person who has the key to decode it.

2. What is DES?

A. Data Encryption Standard is a symmetric-key block cipher that divides text into 64-bit blocks to be decoded by the same cryptography key. It was created in the early 1970s by a team from IBM and then accepted by NIST as the Federal Information Processing Standard in the USA.

3. What is the scope of cryptographers?

A. Data privacy and data security is a burning issue in today’s times. A majority of companies in the field of cyber security, computer engineering, or high-security government agencies require cryptographers or coders with a degree in cryptography. Stronger and stronger algorithms are being improved and developed every day. Lattice cryptography developers say that it will protect data from attacks from future quantum computers too.

4. Is Data Science related to Cryptography?

A. Data science is not directly related to Cryptography but both require deep knowledge of coding and programming languages like C, Java, Python, and MATLAB. Both involve the use of statistics to analyze and safeguard data.

5. What is DES replaced with?

A. DES was susceptible to brute force attacks and code-cracking in just a few hours. Triple DES was developed wherein to encrypt data, the DES cipher is used three times. However, a more advanced coding algorithm, Advanced Encryption Standard (AES) was approved by NIST in 2002.

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