Symmetric Key

A symmetric or cryptographic key is a security tool to encrypt and decrypt data. The secret key, which should be the same for the sender and receiver, will be used to scramble and unscramble the data once it is sent. Using a symmetric key instead of an asymmetric one is faster in encrypting and decrypting data since it is shorter.

How a Symmetric Key Works

A symmetric key is a critical component in the secure transfer of data. The symmetric secret key will rearrange the data into an unreadable form, also known as ciphertext, and the receiver will use the same key to decrypt the scrambled data into plaintext. In real-world usage, symmetric key cryptography can send an email message securely. Usually, the sender generates a secret key and encrypts the email message with that key. Once the recipient receives the email message, they use the same secret key to decrypt it. The secret key allows only the sender and recipient to read the message.

Examples of symmetric key algorithms include:

• Advanced Encryption Standard (AES)
• Data Encryption Standard (DES)
• Triple DES (3DES)

Symmetric keys can be used, but not limited to the following applications:

• Securely transferring files
• Secure communication over a network

Advantages and Disadvantages of Using a Symmetric Key

Besides improving security, using symmetric keys has other advantages:

• Easy to implement and use
• Efficient in speed and memory use
• Encrypt large sets of data

Some disadvantages exist when using a symmetric key, and they include:

• If a key gets compromised by a malicious actor, then the encrypted data along with the key is also compromised
• Both sender and receiver must have the same key and this can be difficult if the two parties are not connected