Encryption involves transforming information in a way that renders it indecipherable to unauthorized parties, ensuring that only those with proper authorization can comprehend it.

Symmetric Encryption

Symmetric encryption, also known as ‘secret key encryption, utilizes a passphrase for encoding information and employs the same passphrase for decoding

The most common and widely used form of symmetric encryption is AES, which stands for Advanced Encryption Standard.

Encoding the string “Hello my friend” using the key “tgrdaouardcourty000” yields the following: 654GFG454DSC68B4C24A8FSF231F0C141.

It can only be decoded using the same key. In the case of an online chat, for example, it requires both sides to know the encryption key.

Some other forms of symmetric encryption are for example, RC4 (Rivest Cipher 4), or DES (Data Encryption Standard).

Asymmetric encryption

Asymmetric encryption, commonly known as ‘public key encryption,’ employs a system of private and public keys, adding a layer of complexity compared to shared secret keys. This complexity contributes to enhanced security. Let’s explore this innovative approach.

Each parties owns a private and a public key. The public key can be shared with anyone and will be used to encode information that will be decoded with the private key.

Let’s have an example:

I want to send a message to my friend Johnny.

Johnny sent me his public key so I can encode my message. I then send the encoded message to Maria, and she’ll use his private key (which she won’t share with anyone) to decode my message.

If she wants to reply, she’ll encode the message she wants to send me using my public key, and I’ll use my private key to decode it.

The only risk here is that Johnny (or me) gets his private key stolen, which would allow the thief to have access to our whole discussion.

In the real world, HTTPS and cryptocurrencies heavily rely on this encryption mechanism.

The most common form of asymmetric encryption is RSA, standing for Rivest–Shamir–Adleman (the inventors of it).


Symmetric encryption requires the sharing of sensitive information (the passphrase) for parties to communicate. In contrast, asymmetric encryption involves only the private keys as sensitive information, which are not shared, making it more secure but also more complex. Remembering a simple passphrase is easier than recalling a lengthy and seemingly random private key.