Cryptography is the use of techniques to transform readable data into an incomprehensible form to prevent unauthorized parties from understanding the information. If the content of a plain text needs to be concealed, encryption is performed. As a result of this process, the plain text changes from a format that anyone can understand to a state that only certain individuals or systems with specific knowledge can comprehend. A key is needed to be able to read an encrypted text. The process of converting the encrypted text back into plain text using these keys is called decryption. There are various encryption algorithms.
1- Symmetric Encryption Algorithms
2- DES (Data Encryption Standard)
3- AES (Advanced Encryption Standard)
4- Blowfish
5-Asymmetric Encryption Algorithmsf-
6-DH (Diffie-Helman)
7- RSA (Rivest–Shamir–Adleman)
8- Keyless Algorithms
SYMMETRIC ENCRYPTION ALGORITHMS
A single secret key is used for encryption and decryption with this algorithm. The systems/individuals performing the encryption and decryption know the key used. The secret plaintext is sent to the receiver along with the agreed upon secret key and the decryption process is performed. One of the most important advantages is that it is fast. Due to its simple operations, implementation on electronic systems is quite straightforward. In addition, the length of the key used and therefore the number of bits is low.
Strengths:
1- Symmetric Encryption Algorithms
2- DES (Data Encryption Standard)
3- AES (Advanced Encryption Standard)
4- Blowfish
5-Asymmetric Encryption Algorithmsf-
6-DH (Diffie-Helman)
7- RSA (Rivest–Shamir–Adleman)
8- Keyless Algorithms
SYMMETRIC ENCRYPTION ALGORITHMS
A single secret key is used for encryption and decryption with this algorithm. The systems/individuals performing the encryption and decryption know the key used. The secret plaintext is sent to the receiver along with the agreed upon secret key and the decryption process is performed. One of the most important advantages is that it is fast. Due to its simple operations, implementation on electronic systems is quite straightforward. In addition, the length of the key used and therefore the number of bits is low.
Strengths:
- Algorithms are fast
- Used together with hardware
- Secure
Weaknesses:
- Secure key distribution is difficult
- Capacity problems exist
- Securely performing authentication and integrity principles is difficult
This encryption type is divided into two as block encryption and stream encryption. Block encryption algorithms process the data in blocks of fixed length. Encryption is sometimes independent and sometimes interdependent. There is no internal memory. Therefore, it is also called memoryless encryption. It is generally preferred in applications that require integrity control. Stream encryption algorithms take the data as a bit stream. A key stream is generated with the help of a generator and key. Key stream generation depends on time and therefore these algorithms are also called stateful encryption.
DES
It is a block encryption algorithm. It performs encryption by processing the text in fixed length blocks. Although it has a 64-bit key length, it uses 56-bit symmetric cryptography. It is considered inadequate and disreputable for today's technology. It was cracked in 2000.
AES
It is a more reliable system compared to DES. It was developed in 2001. They strengthened the weaknesses of DES to create it. It is a block encryption algorithm. It can have three different key lengths of 128, 192, 256 bits. It is the most commonly used symmetric encryption algorithm. It is resistant to brute force attacks.
BLOWFISH
Blowfish has a block size of 64 bits and a key length varying from 32 bits to 448 bits. It was designed to replace DES as it started to become inadequate. It is considered a successful algorithm in terms of its efficiency in high encryption and routine user applications such as e-mail.
ASYMMETRIC ENCRYPTION ALGORITHMS
In a multi-user system using symmetric algorithms, distributing the same key to all users can be problematic in terms of security. Giving each user a different key will be cumbersome as there will be many different keys in the system. Asymmetric encryption algorithms have been developed to solve these problems. The encryption key is called the public key and the decryption key is called the private key. Public keys can be given to everyone, but which key belongs to whom must be known. Therefore, certificates are used. The private key, on the other hand, is only available to the person/system that will decrypt the cipher. The biggest disadvantage is that it is slow. In addition, due to the use of very large numbers, adapting to hardware structures is much more difficult.
DH
In 1976, it was the first asymmetric encryption algorithm found by Diffie and Helman. DH is a protocol that allows two participants to agree on a shared secret key over an insecure channel (securely) without any prior exchange of information.
RSA
In addition to key distribution, RSA also performs encryption and decryption operations. RSA is an encryption technique based on the difficulty of working with very large integers. RSA, a public key encryption technique, is based on generating and processing very large integers. RSA is an encryption technology in which keys are produced from values created by optimizing integers used for both message encryption and digital signature, more preferred in commercial applications. A 1024-bit key can be used as a sufficient encryption technique for simple applications.
KEYLESS ALGORITHMS
In addition to symmetric and asymmetric encryptions, there are also algorithms that do not use a key as input. These algorithms are generally not used alone in a system. They are designed to assist other symmetric and asymmetric algorithms in the system.
Source:https://www.turkhackteam.org/konular/sifreleme-temelleri-ve-turleri.2043949/
DES
It is a block encryption algorithm. It performs encryption by processing the text in fixed length blocks. Although it has a 64-bit key length, it uses 56-bit symmetric cryptography. It is considered inadequate and disreputable for today's technology. It was cracked in 2000.
AES
It is a more reliable system compared to DES. It was developed in 2001. They strengthened the weaknesses of DES to create it. It is a block encryption algorithm. It can have three different key lengths of 128, 192, 256 bits. It is the most commonly used symmetric encryption algorithm. It is resistant to brute force attacks.
BLOWFISH
Blowfish has a block size of 64 bits and a key length varying from 32 bits to 448 bits. It was designed to replace DES as it started to become inadequate. It is considered a successful algorithm in terms of its efficiency in high encryption and routine user applications such as e-mail.
ASYMMETRIC ENCRYPTION ALGORITHMS
In a multi-user system using symmetric algorithms, distributing the same key to all users can be problematic in terms of security. Giving each user a different key will be cumbersome as there will be many different keys in the system. Asymmetric encryption algorithms have been developed to solve these problems. The encryption key is called the public key and the decryption key is called the private key. Public keys can be given to everyone, but which key belongs to whom must be known. Therefore, certificates are used. The private key, on the other hand, is only available to the person/system that will decrypt the cipher. The biggest disadvantage is that it is slow. In addition, due to the use of very large numbers, adapting to hardware structures is much more difficult.
DH
In 1976, it was the first asymmetric encryption algorithm found by Diffie and Helman. DH is a protocol that allows two participants to agree on a shared secret key over an insecure channel (securely) without any prior exchange of information.
RSA
In addition to key distribution, RSA also performs encryption and decryption operations. RSA is an encryption technique based on the difficulty of working with very large integers. RSA, a public key encryption technique, is based on generating and processing very large integers. RSA is an encryption technology in which keys are produced from values created by optimizing integers used for both message encryption and digital signature, more preferred in commercial applications. A 1024-bit key can be used as a sufficient encryption technique for simple applications.
KEYLESS ALGORITHMS
In addition to symmetric and asymmetric encryptions, there are also algorithms that do not use a key as input. These algorithms are generally not used alone in a system. They are designed to assist other symmetric and asymmetric algorithms in the system.
Source:https://www.turkhackteam.org/konular/sifreleme-temelleri-ve-turleri.2043949/
