Symmetric Vs Asymmetric Encryption – Which One Is Better?

Since data breaches and data tampering by hackers are on the higher end, safeguarding digital information becomes a priority. Encryption is one such web security that can shield these attacks.

Encryption is a technical term, and a layman or a non-technical person who is new to cryptography, algorithms, and encryptions find it difficult to decide which encryption software needs to be utilized to secure sensitive information. It becomes more of a challenge when such a user needs to decide between the two types of encryptions, i.e. symmetric encryption and asymmetric encryption.

Both these types of encryptions help secure communications between server and browser.  Before moving forward to definitions and differences between these two types, let’s clear the basic concepts first.

About Algorithms:

Algorithms are formulas that help in solving problems in a computer, specifically for data theft and other issues. The algorithm converts data into ciphertext, which can be decoded with a key, which is used for converting data in plain text.

About Cryptography:

Computer encryption is based on the cryptography method, which helps to maintain the confidentiality of data. These cryptosystems use cryptographic algorithms for encrypting plain texts to ciphertexts and decrypting ciphertexts to readable formats.

 Encryption & Cryptographic Keys:

With the rise in technology, hackers too use sophisticated techniques to grab data, and hence encryption techniques use complex algorithms for converting information into an incoherent format.

Cryptographic keys are used in the encryption and decryption process.

Symmetric Encryption:

This is the simplest and most convenient method of encryption. This encryption method uses only one secret key (Symmetric Key) to encrypt and decrypt data. This Symmetric key is owned by both the parties for encoding and decoding the data. Before the sender sends the message, they use this key to encrypt information, which is later used by the receiver to decrypt the information.

The Symmetric Key is a combination of alphabets, words, numbers, etc. which look like rubbish characters.

Here, in Symmetric Encryption, both parties must be aware of how to use the secret key and communicate information. Since this key is secretive, the distribution of the key is a challenge in itself.

Important Tips:

•     You cannot afford to misplace or lose this secret key. Else it may land in the hands of malicious people who can decrypt and misuse your information.
•     Distribution of keys to more connected users can cause key management issues.
•     Confidentiality can be ensured, but data integrity is lacking in this type of encryption.
•     Less complex and faster encryption process than asymmetric encryption, hence it is preferred in bulk data transfers.
•     Algorithms of symmetric encryption use block ciphers or stream ciphers.
•     Symmetric encryption algorithms include AES-128, AES-192, and AES-256.
•     It is used to secure data in hard disks, computers, archives, laptops, etc.

Asymmetric Encryption:

Asymmetric Encryption or Public Key Cryptography is the most complex and latest encryption mode. Here instead of one secret key, two cryptographic keys which are generated at the same time, are used for data security, and hence its complexity increases. These keys are called Public Key and Private Key.

As the name states, Public Key can be sent to many users who wish to send messages, whereas the Private Key is secured with the owner of the Public Key. Messages can be encrypted with the Public Key, whereas they can be decrypted with the corresponding Private Key pair. So even if a person has a Public Key and has picked up a message by intruding, they cannot decrypt the same without the Private Key.

You can send encrypted messages using the Public key, and only the intended recipient can intercept the message with a Private Key.

Important Tips:     

•     Key pair (Public Key & Private Key) is generated at the same time using mathematical algorithms.
•     Functions of these keys are interchangeable, i.e. if the Public Key is used for encryption and the Private Key is used for decryption, the vice-versa situation is also true. i.e. if the Private Key is used for encryption, then the Public Key can be used for decryption.
•     This encryption assures authenticity, confidentiality, data storage, and non-repudiation of digital communications.
•     It is slower than Symmetric Encryption since it requires more power and it is more complex, but it’s more secure than Symmetric Encryption.
•     It is not suitable for bulk data transfers.
•     This encryption is usually used in digital signatures, digital certificates, and other daily digital communication channels.
•     Asymmetric algorithms include RSA, PKCS, ElGamal, Elliptic Curve Techniques, etc.

Symmetric Encryption Vs Asymmetric Encryption:

A few significant differences between the two types of encryption are:

1.   Cryptographic Keys:

Symmetric Encryption requires just one key for both the encryption and decryption of sensitive data.

Asymmetric Encryption requires a pair of keys, i.e. 2 keys for encrypting and decrypting information. The Public Key is used for encrypting information, whereas the Private Key is used for decrypting the same.

2.   Primary Motive:

Symmetric Encryption is very useful when bulk data needs to be transferred on digital channels.

Asymmetric Encryption is the best option when you need a secure environment for data transfer.

3.   Speed and Ease:

Symmetric Encryption is quick and easy since only one key is required in the entire process.

Asymmetric Encryption is slow and complex since two keys are required in the entire process.

4.   Algorithms:

Symmetric encryption uses AES, DES, QUAD, RC4, and 3DES algorithms.

Asymmetric encryption uses RSA, DSA, EL GAMAL, ECC, and Diffie Hellman algorithms.

5.   Key Length:

Symmetric Key lengths are 128-bit and 256-bit depending on security requirements.

Asymmetric Key lengths are larger, i.e. 1024-bit and 2048-bit.

6.   Security:

In Symmetric Encryption, the secret key is shared, and hence the risk is more.

In Asymmetric Encryption, the Private Key is not shared and the process is more secured.

7.   Cipher Text Size:

In Symmetric Encryption the size of ciphertext is the same or smaller than the plain text.

In Asymmetric Encryption, the size of ciphertext is the same or larger than the plain text.

8.   Resource Utilization:

In Symmetric Encryption resource utilization is low. Hence it’s speedy.

In Asymmetric Encryption resource utilization is high, and hence the process is slow.

Which Encryption is Better?

This is a tough question because it is very difficult to compare their cryptographic strengths. Though the asymmetric key lengths are longer than the symmetric key lengths, it doesn’t prove that asymmetric encryption is a tough nut as compared to symmetric encryption.

Both are vital in their ways. When we focus on the speed factor, Symmetric Encryption wins the race, whereas where data confidentiality and authenticity are top priorities, asymmetric encryption is better. Even key distribution becomes a problem in the case of Symmetric Encryption, whereas secrecy of the Private Key can be maintained easily. Hence modern web securities have realized that a combination of both these encryptions works the best for securing data.

Example:

•     SSL certificates use both encryptions to secure websites.
•     File transfer systems use the combination of both for secured file transfers.
•     Messaging applications like WhatsApp use Asymmetric Encryption for encrypted communications, whereas the remaining communication progresses using Symmetric Encryption.

Final Thoughts:

In modern cryptography, new algorithms and formulas evolve to secure data from eavesdroppers.

Since there are pros and cons in both these types of encryptions, go for the process which fits the best in criterion. Utilize the encryption algorithm which is the best for the defined task and secure your digital network.