Difference Between Symmetric and Asymmetric Encryption

by Tashina

Most of us are aware that encryption is changing a message from its readable form to an encoded message to prevent someone else from reading it. This message can only be decoded by someone who knows the algorithm behind it. Thus, it provides data security. There are two types of encryption methods, i.e. symmetric and asymmetric encryption. Symmetric encryption is an old technique but asymmetric encryption is relatively new which overcame the data security flaws of symmetric. The main difference between these two encryption techniques is the use of keys to encrypt and decrypt the message.

Symmetric Key Encryption

In symmetric encryption, there is only one key that for encrypting and decrypting the message. In other words, the data security of symmetric key encryption is less because if we figure out the key for encryption, the message can be easily decrypted. You will need a safe path to transfer the encryption key to the other end for decryption. However, this encryption is generally fast than asymmetric.

Asymmetric Key Encryption

In asymmetric key encryption, there are two different keys for encryption and decryption of message. It is based on public encryption key and private decryption key concept. Thus, it provides more data security in sending encrypted message but, it is slower than symmetric key encryption.

Some Other Differences

Other than the key and speed of symmetric and asymmetric encryption, there are some other differences between the two methods.

  • Size of cipher text

In symmetric encryption, the size of cipher text is smaller than the original text. On the other hand, in asymmetric, the size of cipher text is larger than the original.

  • Usage

Symmetric encryption is preferable when we need to transfer large amount of data, whereas asymmetric encryption is better to use when we need to send small amount of data.

  • Resource utilization

In symmetric encryption resources utilization is low as compared to the resource utilization in asymmetric encryption.

  • Length of keys

In symmetric encryption the length of keys is usually 128 or 256 bits whereas in asymmetric encryption, the length of key is large. The recommended RSA key length is 2048 bits.


The examples for symmetric encryption algorithms include: RC4, AES, DES, 3DES, and many more.  Likewise, the examples for asymmetric encryption algorithm include: RSA, Diffie-Hellman, ECC, etc.

Encryption Provides Data Security

Data security is very crucial and you should choose your encryption technique very carefully. Both symmetric and asymmetric encryptions have their own benefits and flaws. The method which best suits your needs should be given priority.

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