Comparison of Various Encryption Algorithms and Techniques for Securing Data
Read time: 6 minutes

Summary of the algorithms
Performance of the algorithms
Characteristics of algorithms

Table 1 summarizes the main features of each encryption algorithm, with what we believe is a fair overview of the current security status of the algorithm.
Factors | RSA | DES | 3DES | AES |
---|---|---|---|---|
Created By | In 1978 by Ron Rivest, Adi Shamir, and Leonard Adleman | In 1975 by IBM | In 1978 by IBM | In 2001 by Vincent Rijmen and Joan Daemen |
Key Length | It depends on the number of bits in modulus n, where n = p*q | 56 bits | 168 bits (k1, k2, and k3) 112 bits (k1 and k2) | 128, 192, or 256 bits |
Rounds | 1 | 16 | 48 | 10-128 bit key, 12-192 bit key, 14-256 bit key |
Block Size | Variable | 64 bits | 64 bits | 128 bits |
Cipher Type | Asymmetric Block Cipher | Symmetric Block Cipher | Symmetric Block Cipher | Symmetric Block Cipher |
Speed | Slowest | Slow | Very Slow | Fast |
Security | Least Secure | Not Secure enough | Adequate Security | Excellent Security |
Table 1: Characteristics of commonly used encryption algorithms
Comparison
- CPU processing speed for encrypting and decrypting data.
- Rate of key generation.
- Key size.
- Security consideration.
- Efficient on the hardware and software in case of implementation.
- The amount of memory required to hold the data in the encryption process.
- Number of users accommodated by the model.
- Time required by the model to recover the data in case of key failure.
- Time available to the hacker to produce various types of attacks.
- The complexity of algorithm technique.

Formulation and Case Study
Case Study
AES Design

Rounds
No. | Key Size | No of Rounds |
---|---|---|
1 | 128 bits | 10 |
2 | 192 bits | 12 |
3 | 256 bits | 14 |
- Substitute Bytes
- Shift Rows
- Mix Columns
- Add Round Key

Encryption with AES
- Initial RoundAdd Round Key
- Main Round
- Sub Bytes
- Shift Rows
- Mix Columns
- Add Round Key
- Final Round:
- Sub Bytes
- Shift Rows
- Add Round Key
- Add Round Key
This is the only phase of AES encryption that directly operates on the AES round key. In this operation, the input to the round is exclusive-or with the round key.
- Sub Bytes
Involves splitting the input into bytes and passing each through a Substitution Box or S-Box. Unlike DES, AES uses the same S-Box for all bytes. The AES S-Box implements inverse multiplication in Galois Field 2.
- Shift Rows
Each row of the 128-bit internal state of the cipher is shifted. The rows in this stage refer to the standard representation of the internal state in AES, which is a 4×4 matrix where each cell contains a byte. Bytes of the internal state is placed in the matrix across rows from left to right and down columns.
- Mix Columns
Provides diffusion by mixing the input around. Unlike Shift Rows, Mix Columns performs operations splitting the matrix by columns instead of rows. Unlike standard matrix multiplication, Mix Columns performs matrix multiplication per Galois Field 2.
Decryption with AES
- Inverse Final Round
- Add Round Key
- Shift Rows
- Sub Bytes
- Inverse Main Round
- Add Round Key
- Mix Columns
- Shift Rows
- Sub Bytes
- Inverse Initial Round
- Add Round Key