Asymmetric vs symmetric encryption: What’s the difference?
Both asymmetric and symmetric encryption are being used by businesses to protect their information. But what are the differences? Read to find out.
The growth in information security has given rise to many patterns and techniques for protecting valuable information from being deciphered by cybercriminals and wrong recipients. Every organization deals with information and data transfers from one point to another. As a result, a lot of effort is being spent on securing this information. That’s why today we hear terms like encryption, cryptography, encoding and decoding — terms that point toward the security of transmitted data from one end to another.
Although these terms are related, this article presents an exposition of two main encryption paths organizations use to ensure the transfer of important information from one point to another.
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What is encryption?
Encryption is the process of turning human-readable texts into encrypted data to protect the data from being decoded easily. Put more technically, encryption involves encoding plain texts into another form known as ciphertext.
Encrypted data makes it safe for individuals, organizations or teams to pass information to one another without fear of exposing the data to unintended recipients. Encryption comes in two main forms: Asymmetric and symmetric.
What is asymmetric encryption?
Asymmetric or public key cryptography is the form of encryption that involves using public and private keys for encryption and decryption. In asymmetric encryption, the sender uses the public key to encode the information in a non-readable form, which can only be decrypted or read with a secret key. In sending encrypted data from the public key scheme, the receiver needs a secret key to access the encrypted data.
With asymmetric encryption, there is no worry about what a malicious individual can do to your encrypted data as long as you have the secret key for the decryption. Some popular asymmetric key encryption include DSA, RSA, PKCS and EIGamal.
Pros and cons of asymmetric encryption
Pros of asymmetric encryption
- Asymmetric encryption allows the recipient to verify and authenticate the origin of a message, making it easy to avoid encrypted messages from an unknown sender.
- Asymmetric key encryption makes room for non-repudiation.
- Public keys in asymmetric encryption are distributed over the public-key servers. So, there is no need to worry about public disclosure of keys as they can’t be used to access your information.
- Using private keys to decrypt a message makes asymmetric encryption more secure.
Cons of asymmetric encryption
- Asymmetric encryption is slower than symmetric encryption.
- If the private key is lost, no one can decrypt the information.
- If a malicious user steals a private key, nothing can be done to prevent access to encrypted data.
What is symmetric encryption?
Symmetric encryption, also dubbed single key encryption, is the type of encryption where a single key can be used to encrypt and decrypt information. In this form of encryption, the receiver uses an agreed shared secret key to decrypt the encrypted data.
Symmetric encryption is the oldest form of encryption and is still relevant in organizations that value the speed of information transmission over security authentication.
Pros and cons of symmetric encryption
Pros of symmetric encryption
- Symmetric encryption is fast and can be set up easily.
- With a secure algorithm, symmetric encryption can be secure.
Cons of symmetric encryption
- Secret keys must be shared with the recipient, and because this is usually done over the internet, there is a possibility that a secret key might be stolen if the network is not secure.
- Both sides of the communication pipeline can easily be compromised if a malicious user steals the secret key.
Key differences between asymmetric and symmetric encryption
| Differences | Symmetric encryption | Asymmetric encryption |
|---|---|---|
| Number of keys used | Uses a single key for encryption. | Uses two keys for encryption: A public and private key. |
| Resource utilization | Low usage of resources for encryption. | High resource utilization for encryption. |
| Size of data | Most suitable for the transfer of big data. | Most efficient for the transfer of small data. |
| Length of key used | Symmetric encryption can take 128 or 256-bit key sizes. | Asymmetric takes more key sizes of RSA 2048-bit or more. |
| Security | Symmetric encryption is considered less secure because it uses a single key for encryption. | Asymmetric encryption remains safer because it uses two keys in encryption and decryption. |
| Algorithms used | AES, RC4, DES and 3DES. | Diffie-Hellman, RSA, ECC algorithms. |
Factors to consider before settling for an encryption method
Type of data
It’s vital to consider the type of information to be encrypted before deciding on the type of encryption that suits your organization. For instance, classified or highly valued information should be encrypted with asymmetric encryption as it offers better security.
Consider speed and efficiency
There is a need to consider if your organization needs to move encrypted information faster. If this is the case, symmetric encryption could be a better option.
Security of information
If your organization is in the business of transmitting highly-classified information, you should go the way of asymmetric encryption, as it offers more information security.
