Difference between AES and DES Ciphers

Both DES and AES are symmetric-key block ciphers that are used in encryption where just one key (the secret key) is utilized to encode and decode electronic data. The key must be exchanged between the organizations communicating using symmetric encryption so that it can be utilized in the decryption process.

Difference between AES and DES ciphers

It stands for Advanced Encryption Standard, developed in 2001. As triple-DES was found to be slow, AES was created and is six times faster than the triple DES. It is one of the most widely used symmetric block cipher algorithm used nowadays. It works on bytes rather than bits.

What is DES?

It stands for Data Encryption Standard, developed in 1977. It is a multi-round cipher that divides the full text into 2 parts and then work on each part individually. It includes various functionality such as Expansion, Permutation, and Substitution, XOR operation with a round key.

AES and DES are both examples of symmetric block ciphers but have certain dissimilarities.

AES	DES
1.	AES stands for Advanced Encryption Standard	DES stands for Data Encryption Standard
2.	The date of creation is 2001.	The date of creation is 1977.
3.	Byte-Oriented.	Bit-Oriented.
4.	Key length can be 128-bits, 192-bits, and 256-bits.	The key length is 56 bits in DES.
5.	Number of rounds depends on key length: 10(128-bits), 12(192-bits), or 14(256-bits)	DES involves 16 rounds of identical operations
6.	The structure is based on a substitution-permutation network.	The structure is based on a Feistel network.
7.	The design rationale for AES is open.	The design rationale for DES is closed.
8.	The selection process for this is secret but accepted for open public comment.	The selection process for this is secret.
9.	AES is more secure than the DES cipher and is the de facto world standard.	DES can be broken easily as it has known vulnerabilities. 3DES(Triple DES) is a variation of DES which is secure than the usual DES.
10.	The rounds in AES are: Byte Substitution, Shift Row, Mix Column and Key Addition	The rounds in DES are: Expansion, XOR operation with round key, Substitution and Permutation
11.	AES can encrypt 128 bits of plaintext.	DES can encrypt 64 bits of plaintext.
12.	It can generate Ciphertext of 128, 192, 256 bits.	It generates Ciphertext of 64 bits.
13.	AES cipher is derived from an aside-channel square cipher.	DES cipher is derived from Lucifer cipher.
14.	AES was designed by Vincent Rijmen and Joan Daemen.	DES was designed by IBM.
15.	No known crypt-analytical attacks against AES but side channel attacks against AES implementations possible. Biclique attacks have better complexity than brute force but still ineffective.	Known attacks against DES include Brute-force, Linear crypt-analysis, and Differential crypt-analysis.
16.	It is faster than DES.	It is slower than AES.
17.	It is flexible.	It is not flexible.
18.	It is efficient with both hardware and software.	It is efficient only with hardware.

Last Updated : 24 Jan, 2023

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Difference between AES and DES Ciphers

Both DES and AES are symmetric-key block ciphers that are used in encryption where just one key (the secret key) is utilized to encode and decode electronic data. The key must be exchanged between the organizations communicating using symmetric encryption so that it can be utilized in the decryption process.

Go through this article to find out the features of AES and DES ciphers and how they differ from each other.

What is DES Cipher?

The Data Encryption Standard, often known as DES, is a symmetric key block cypher developed by IBM in 1977.

• Plaintext is divided into two halves in DES encryption, and then DES uses a 64-bit plaintext and a 56-bit key to generate a 64-bit ciphertext, which is an encrypted representation of the data.
• The key length used for encryption in DES is 56 bits, although the block size is 64 bits (the remaining 8 bits are check bits only; they are not used by the encryption algorithm). DES entails 16 rounds of identical procedures, regardless of key length.
• Because the amount of operations in DES is fixed and no permutation combinations are permitted, it is easier to break the encryption, making it less secure than AES.

DES is a symmetric key algorithm used to encrypt digital data. Its short key length of 56 bits makes it too weak to secure most current applications that is based on encryption.

What is AES Cipher?

Advanced Encryption Standard, or AES, is a symmetric key block cipher developed by Vincent Rijmen and Joan Daemen in 2001. AES is implemented worldwide, both in hardware and software, to encrypt sensitive data. AES is widely used while transmitting data over computer networks, particularly in wireless networks.

• AES uses a 128-bit plaintext and a 128-bit secret key to create a 128-bit block, which is then processed to produce 16 bytes (128-bit) ciphertext.
• In the case of AES, the key length might be 128 bits, 192 bits, or 256 bits, with 10 rounds (128 bits), 12 rounds (192 bits), or 14 rounds (256 bits).
• AES, on the other hand, is more secure than DES encryption and has become the de facto international standard.

The encryption process of Advanced Encryption Standard is based upon substitution and permutation operations in iterative manner. The 16 bytes of data are arranged in a matrix of four columns and four rows. On this matrix, AES performs rounds of substitution-permutation operations.

Each of these rounds uses a different cipher key, which is calculated from the original AES key. The number of rounds of operations depends upon the size of the key in the following manner –

• For 128-bit cipher key, 10 rounds
• For 192-bit cipher key, 12 rounds
• For 256-bit cipher key, 14 rounds

Difference between AES and DES ciphers

The following table highlights the major differences between AES and DES Ciphers.

Conclusion

To conclude, both AES and DES are symmetric key block ciphers, however AES cipher is the de-facto standard of encryption and it is more secure than DES cipher.

AES vs DES Encryption: Why Advanced Encryption Standard (AES) has replaced DES, 3DES and TDEA

Every so often, we encounter someone still using antiquated DES for encryption. If your organization hasn’t switched to the Advanced Encryption Standard (AES), it’s time for an upgrade. To better understand why: let’s compare AES vs DES encryption:

Data Encryption Standard (DES)

What is DES encryption?

DES is a symmetric block cipher (shared secret key), with a key length of 56-bits. Published as the Federal Information Processing Standards (FIPS) 46 standard in 1977, DES was officially withdrawn in 2005.

The federal government originally developed DES encryption over 35 years ago to provide cryptographic security for all government communications. The idea was to ensure government systems all used the same, secure standard to facilitate interconnectivity.

Why DES is no longer effective

To show that the DES was inadequate and should not be used in important systems anymore, a series of challenges were sponsored to see how long it would take to decrypt a message. Two organizations played key roles in breaking DES: distributed.net and the Electronic Frontier Foundation (EFF).

• The DES I contest (1997) took 84 days to break the encrypted message using a brute force attack.
• In 1998, there were two DES II challenges issued. The first challenge took just over a month and the decrypted text was “The unknown message is: Many hands make light work”. The second challenge took less than three days, with the plaintext message “It’s time for those 128-, 192-, and 256-bit keys”.
• The final DES III challenge in early 1999 only took 22 hours and 15 minutes. Electronic Frontier Foundation’s Deep Crack computer (built for less than $250,000) and distributed.net’s computing network found the 56-bit DES key, deciphered the message, and they (EFF & distributed.net) won the contest. The decrypted message read “See you in Rome (Second AES Candidate Conference, March 22-23, 1999)”, and was found after checking about 30 percent of the key space – finally proving that DES belonged to the past.

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Even Triple DES is not enough protection

Triple DES (3DES) – also known as Triple Data Encryption Algorithm (TDEA) – is a way of using DES encryption three times. But even Triple DES was proven ineffective against brute force attacks (in addition to slowing down the process substantially).

According to draft guidance published by NIST on July 19, 2018, TDEA/3DES is officially being retired. The guidelines propose that Triple DES be deprecated for all new applications and disallowed after 2023.

Advanced Encryption Standard (AES)

What is AES encryption?

Published as a FIPS 197 standard in 2001. AES data encryption is a more mathematically efficient and elegant cryptographic algorithm, but its main strength rests in the option for various key lengths. AES allows you to choose a 128-bit, 192-bit or 256-bit key, making it exponentially stronger than the 56-bit key of DES.

In terms of structure, DES uses the Feistel network which divides the block into two halves before going through the encryption steps. AES on the other hand, uses permutation-substitution, which involves a series of substitution and permutation steps to create the encrypted block. The original DES designers made a great contribution to data security, but one could say that the aggregate effort of cryptographers for the AES algorithm has been far greater.

Why AES replaced DES encryption

One of the original requirements from the National Institute of Standards and Technology (NIST) for the DES replacement algorithm was that it had to be efficient both in software and hardware implementations. (DES was originally practical only in hardware implementations.) Java and C reference implementations were used to do performance analysis of the algorithms. AES was chosen through an open competition with 15 candidates from as many research teams around the world, and the total amount of resources allocated to that process was tremendous.

Finally, in October 2000, a NIST press release announced the selection of Rijndael as the proposed Advanced Encryption Standard (AES).

What are the differences between DES vs AES encryption?

DES	AES
Developed	1977	2000
Key Length	56 bits	128, 192, or 256 bits
Cipher Type	Symmetric block cipher	Symmetric block cipher
Block Size	64 bits	128 bits
Security	Proven inadequate	Considered secure

So the question remains for anyone still using DES encryption… How can Precisely help you make the switch to AES vs DES? Check out Assure Security to get started.

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