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View the Lessons →**Symmetric encryption** is a form of encryption where the same key is used to encrypt and decrypt the message. This contrasts from asymmetric or public-key encryption, which uses one key to encrypt a message and another key to decrypt the message.

Symmetric encryption is a kind of computerized cryptography using a particular encryption key to conceal an electronic message. Its data conversion utilises a mathematical procedure along with a private key, which results in the failure to make sense out of a message. Symmetric encryption is a two-way algorithm because the mathematical procedure is turned back when decrypting the message along with using the same private key.

Symmetric encryption is also referred to as private-key encryption and secure-key encryption.

This is the most straightforward form of encryption that comprises of only one private key to cipher and decipher information. Symmetrical encryption is an old and best-known practice. It uses a private key that can either be a number, a word or a string of random letters. It is mixed with the plain text of a message to alter the content in a certain way. The sender and the recipient should know the private key that is used to cipher and decipher all the messages.

## Examples of Symmetric Encryption

- Blowfish
- AES (Advanced Encryption Standard)
- RC4 (Rivest Cipher 4)
- DES (Data Encryption Standard)
- RC5 (Rivest Cipher 5)
- RC6 (Rivest Cipher 6)

The most commonly used symmetric algorithm is AES-128, AES-192 and AES-256.

The main drawback of the symmetric key encryption is that all individuals engaged in the activity have to exchange the key used to encrypt the data before they can decrypt it.

### Types of Symmetric Encryption

- Block algorithms are used to blocks of electronic data. Specified set lengths of bits are altered, while concurrently using the designated private key. This key is then used to each block. However, when network stream data is being encrypted, the encryption system retains the data in its memory components while waiting for the complete blocks. The time in which the system waits can lead to a certain security gap and may undermine data protection. The solution includes a process where the block of data could be decreased and merged with preceding encrypted data block contents until the rest of the blocks arrive. This process is known as feedback. When the entire block is received, then it is encrypted.
- Stream algorithms are not retained in the encryption system memory but arrive in data stream algorithms. This type of procedure is considered somewhat safer since a disk or system is not retaining the data without encryption in the memory components.

## Difference Between Symmetric and Asymmetric Encryption

- Symmetric encryption uses a singular key that has to be shared among the people who need to receive the message while asymmetrical encryption uses a pair of public key and a private key to encrypt and decrypt messages when communicating.
- Symmetric encryption is an old practice while asymmetric encryption is relatively new.
- Asymmetric encryption was brought in to fix the inherent problem of the need to share the key in symmetric encryption model, removing the need to share the key by using a pair of public-private keys.
- Asymmetric encryption eats up more time than the symmetric encryption.

When it comes to encryption, the latest systems may inevitably be the best fit. You should always use the encryption procedure that is applicable for the task at hand. In fact, as cryptography takes a new swing, new procedures are being established in a bid to catch up with the eavesdroppers and protect information to improve privacy. Hackers are destined to make it hard for experts in the coming years, thus expect more from the cryptographic community.