When it comes to data protection and encryption, two popular methods are widely used: symmetric key cryptography and asymmetric key cryptography. Both play a big role in cybersecurity, but they work in very different ways. While symmetric encryption uses a single key to lock and unlock data, asymmetric encryption uses a public and private key pair.
In this blog, we’ll break down the key differences between symmetric and asymmetric encryption, how they work, and where each method is used in real life — from secure messaging to online transactions and more. If you’re curious about how your digital data stays safe, you’re in the right place.
Table of Contents
What is Cryptography?
So, what exactly is cryptography? In simple words, it’s a way of hiding information so that only the right person can read it. It’s like turning a message into a secret code that no one else can understand, unless they have the key to unlock it.
Cryptography is used everywhere today, from WhatsApp messages to online banking, computer passwords, and even shopping on websites.
The main idea? To protect data from hackers or anyone who shouldn’t be able to see it.
Terminologies used in Cryptography
1. Encryption
Encryption is the process of coding or locking up data or information using cryptography. The data that has been locked is said to be encrypted.
2. Decryption
Decryption is the process of unlocking or decoding encrypted data/information using cryptographic techniques.
3. Key
A password or string of characters used to encrypt and decrypt data is referred to as a key.
Different types of keys are used in cryptography. Only the sender and receiver are aware of the information. For example, symmetric-key cryptography uses secret keys for both encryption and decryption.
Types of Cryptography
There are mainly two types of cryptography used in cybersecurity:
- Symmetric Encryption (also called secret key cryptography)
- Asymmetric Encryption (also known as public key cryptography)
Each one works a bit differently depending on how they use keys. Let’s break them down one by one.
1. Symmetric Encryption
Symmetric encryption is the simplest form of cryptography. It uses one single secret key to both lock (encrypt) and unlock (decrypt) the information. Therefore, both the sender and receiver must have the same key and keep it secure.
Key Features:
- Super fast and efficient
- Best for encrypting large amounts of data
- Used in things like databases, credit card systems, and file storage
- Popular algorithms: AES, DES
Example of Symmetric Encryption
Imagine you write a secret note to a friend, and you both have the same key to a locked box. You lock the note inside it, and your friend uses the same key to open it. Here, only you and your friend can access the note. That’s symmetric encryption.
The only problem? If someone steals the key while it’s being shared, they can read the message too.
2. Asymmetric Encryption
Asymmetric encryption is a bit more advanced. Instead of one key, it uses two keys:
- A public key that is being shared openly with anyone
- A private key that is kept secret and only known to the owner
Anyone can use the public key to lock the message, but only the private key can unlock it.
Key Features:
- More secure than symmetric (no need to share secret keys)
- Used in email encryption, SSL/HTTPS websites, and digital signatures
- Popular algorithms: RSA, ECC
Example of Asymmetric Encryption
It’s like you have a public mailbox. Anyone can drop letters into it (public key), but only you have the key to open and read them (private key).
Difference between Symmetric and Asymmetric key cryptography
So, when it comes to the distinction between symmetric and asymmetric encryption, which is more secure? Asymmetric encryption is slower than symmetric encryption, but it is more stable. They’re both effective in their own ways, and depending on the task, one or both of them can be used separately or together.
The table below compares symmetric and asymmetric encryption in greater detail. Some of these differences can be attributed to the various types of keys used, while others can be attributed to the time required to compute the encryption methods.
| Symmetric Encryption | Asymmetric Encryption |
| Private key cryptography or secret-key cryptography are other names for it. | Asymmetric key cryptography, also known as conventional cryptography or public-key cryptography, is a type of cryptography. |
| Key lengths are typically 128 or 256 bits, depending on the security criteria. | The key length is even longer; the recommended RSA key size for asymmetric encryption is 2048 bits or greater. |
| The encryption method can be completed quickly because it is a simple procedure. | It is a much more difficult and time-consuming mechanism than symmetric key encryption. |
| The mysterious key has been revealed. As a result, the likelihood of compromise rises. | Because the private key is not shared, the overall process is more reliable than symmetric encryption. |
Advantages of Symmetric Cryptography
- Symmetric cryptosystems are faster.
- Encrypted data can be transmitted over a network in Symmetric Cryptosystems even if it is certain that the data will be intercepted. Because no key is sent with the files, data decryption is impossible.
- To confirm the receiver’s existence, a symmetric cryptosystem employs password authentication.
- A message can only be decrypted by a device that has a hidden key.
- Prevents widespread message security breaches. For communication with each party, a separate secret key is used. Only communications from a specific pair of sender and recipient are affected when a key is corrupted. Communication with others is always safe.
- This type of encryption is simple to implement. To begin encrypting and decrypting messages, users only need to specify and exchange the secret key.
- Your files can be encrypted and decrypted. There is no need to create separate keys if you use encryption for messages or data that you only want to access once. For this, single-key encryption is ideal.
- Asymmetric key encryption takes much longer than symmetric key encryption.
- It uses fewer computer resources. Single-key encryption requires fewer computing resources than public-key encryption.
Disadvantages of Symmetric Cryptography
- It is not possible to create digital signatures that cannot be revoked.
- The message’s origin and validity cannot be guaranteed. Messages cannot be proven to have originated from a specific person because both the sender and the recipient use the same key. If there is disagreement, this could be a problem.
- Each party must generate a new shared key in order to communicate. This makes it difficult to handle and secure both of these keys.
Advantages of Asymmetric Cryptography
- There is no need to exchange keys in asymmetric or public key cryptography, which eliminates the key distribution problem.
- The primary benefit of public-key cryptography is that private keys are never exchanged or disclosed to others.
- Digital signatures with revocation capabilities may be provided.
- Message verification is provided by public-key cryptography, which requires the use of digital signatures, allowing the message’s recipient to confirm that the message is indeed from a specific sender.
- The use of digital signatures in public-key cryptography allows the recipient to determine whether or not the message was altered during transit. A digitally signed message cannot be altered without rendering the signature invalid.
Disadvantages of Asymmetric Cryptography
- The slowness of using public-key cryptography for encryption is one disadvantage. Popular secret-key encryption systems are much faster than any widely used public-key encryption technique.
- Public key authentication is strongly recommended/required. Because no one can be certain that a public key corresponds to the person it is supposed to identify, everyone must confirm that their public keys are theirs.
- It consumes more computer resources. It necessitates far more computing resources than single-key encryption.
- A widespread security breach is likely if an intruder obtains a person’s private key and reads his or her entire message.
- The loss of a private key can be irreversible. When a private key is compromised, all incoming messages become unreadable.
Conclusion
As technology grows, so do the tactics of cybercriminals. That’s why new cryptographic algorithms are constantly being developed to outsmart eavesdroppers and keep our data secure. While hackers are becoming more advanced every day, the world of cybersecurity and encryption isn’t sitting still either. From symmetric encryption to asymmetric key cryptography, these tools will continue to evolve and protect sensitive information. The future of cryptography looks promising, and staying updated is key to staying safe online.