Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both encryption of plaintext and decryption of ciphertext.
The keys may be identical or there may be a simple transformation to go between the two keys.
The keys, in practice, represent a shared secret between two or more parties that can be used to maintain a private information link.
This requirement that both parties have access to the secret key is one of the main drawbacks of symmetric key encryption.[Source - wikipedia]
Types of symmetric-key algorithms
- Stream Ciphers
- Block Ciphers
You can search for the detailed description. I am not going in deep here.
Here, with our project we are going to implement one of the symmetric key encryption algorith -
AES - Advanced Encryption Standard
AES uses a single key for both encryption and decryption.