Symmetric Key Encryption – why, where and how it’s used

In today’s cyberspace, there is a constant risk of unauthorized access to various types of data. The greatest risk comes from data in financial and payment systems that can expose personally identifiable information (PII) or payment card information of customers and consumers.

Encryption is critical to protecting personally identifiable information and mitigating the risks faced by organizations that conduct payment transactions on a daily and minute-by-minute basis.
In this article, we’ll discuss symmetric encryption in the banking industry, its benefits, and some of the challenges of key management.

How does symmetric encryption work?

Symmetric encryption works like locking the front door of a home, where only the husband and wife have the key. Even if a neighbor or relative tries to open the door, they can’t unless they use one of the couple’s keys. If another person gets the key from the husband or wife, they can open the door without the couple’s knowledge or presence.

In symmetric encryption, the key used to encrypt a message or file is the same as the key used to decrypt it. The sender of the data encrypts the original data using a symmetric key algorithm and converts it into cipher text. The encrypted message is then sent to the recipient, who uses the same symmetric key to decrypt or open the cipher text, or convert it to readable form.

How a Basic Shift Cipher (Substitution Cipher) Works

A simple way to think about this encryption process is to use a Caesar cipher, known as a substitution or transfer cipher. In this way, Caesar can communicate secretly with his generals without anyone being able to read the message (even if the message carrier is intercepted).

In this case, a cipher, also known as an algorithm, is a number or a series of steps that you would use to convert a plaintext message into an unreadable password. With a simple shift cipher, you can encrypt and decrypt a message by simply shifting a certain amount of space along the alphabet.

Differences between symmetric and asymmetric encryption

  1. Symmetric encryption uses a single key that must be shared with the recipient of the message, while asymmetric encryption uses a pair of public and private keys to encrypt and decrypt the message during communication.
  2. Symmetric encryption is an old technique, while asymmetric encryption is relatively new.
  3. Asymmetric encryption seems to complement the need for shared keys inherent in the symmetric encryption model by using public-private key pairs to eliminate the need for shared keys.
  4. Asymmetric encryption takes a relatively longer time than symmetric encryption.