Difference Between Conventional and Public Key Encryption (With Table)

Whitfield and Hellman authored ‘New Directions in Cryptography’ in 1976, which came from the most remarkable progress in the entire history of the cryptographic world! That feature article presented a breakthrough new concept in community cryptography called Diffie-Hellman key transfer, which seems to have become a basic aspect of today’s cryptography.

However, we are gonna focus on understanding the two types of coding or encryption processes namely; conventional key encryption and public-key encryption with the help of pointers and tables to help you understand them completely.

Conventional vs Public Key Encryption

The difference between conventional and public-key encryption is that the conventional encryption method requires only one decoding key for the successful decoding of the message but, public encryption requires two distinct keys one for encryption and another for decryption. The nature of public key encrypting keys is asymmetrical because it is discrete and needs a proper sequence to decode.

In conventional key encryption, it is thought that deriving the encrypted text alone without a key is literally impossible because it will fail mathematically thus giving a wrong output. As a result, keeping the key hidden is vital.

These encryption methods are used in reality because they are efficient in encoding and decoding data, although they have flaws. The total amount of keys accessible to pick from is one element of these problems. Brute strength assaults are less likely with larger main aspects.

Public key encryption on the other hand is done using a public key, while decryption is done with a private key. The transmitter and receiver of encoded sensitive data have different private keys or can be structurally “similar”. Asymmetric key refers to the use of a public key.

The secret key used by the outer people and the private key which is usually kept at a secured place is the two keys that are needed in public-key cryptography. The public key is used for encryption communications and may be openly distributed among individuals, whereas the secret private key is kept private and only known by the receiver.

Comparison Table Between Conventional and Public Key Encryption

Parameters of ComparisonConventional Key EncryptionPublic Key Encryption
Invented ByThe first cypher to employ a correct encryption key was created according to Giovan Battista Bellaso.Diffie and Hellman invented the public-key cryptosystem model.
Number of KeysOnly one key is required.Two keys are used by the sender and recipient.
Algorithms UsedEither logic algorithms or mathematical algorithms.Both logic and arithmetic algorithms are used.
SymmetrySymmetric in nature.Asymmetric in nature.
SecuritySince it employs a simple cryptosystem and decryption, it is a reasonably quick procedure and less secured.Is secured and more reliable than the traditional conventional key encryption.

What is Conventional Key Encryption?

Conventional key encryption, often known as symmetrical data cryptography or single-key cryptography, is an encryption method that encrypts and decrypts messages by using the same key. The sender encrypts the unencrypted data with the receiver’s private key, which may then be used to execute the code by the recipient.

Because it employs a single private key for the entire cryptosystem, it is a reasonably quick procedure. The primary disadvantage of this commonly used encryption approach is that it would not scale effectively to a lot of users since the transmitter and recipient must agree on a private key before transfer. Because the key is shared across numerous senders and receivers, it is less reliable. Single-key encryption is a fairly ancient concept, which is why it is referred to as a conventional encryption technique.

Because of its simplicity, it is the more popular of the two main types of encryption methods. Because it employs a cryptosystem and decryption, it is a reasonably quick procedure. Inside this encryption scheme, the sender encrypts data with the receiver’s private key, which may then be used to decode the ciphertext by the recipient.

The traditional encryption approach requires both the transmitter and the recipient to know the particular secret key ahead of schedule and to consent on something before the transfer, which presents safety problems and a trust issue, particularly in regards to verification and integrity protection.

What is Public Key Encryption?

Whitfield and Hellman invented the public-key cryptosystem model, which was the first real breakthrough notion in the field of encryption and decryption. A digital system that employs two keys: a public key with an access policy and a private key is defined as public-key cryptography. The key pair can be freely exchanged among users, whereas the secret private key is only accessible to the receiver. A message or information is encrypted using the public key, which is subsequently decrypted with the private key.

Public-key cryptography’s main goal is to offer anonymity, secrecy, and authenticity. Traditional encryption methods are based on basic manipulations on data bits, whereas public-key methods are based on arithmetic operations. Advanced encryption standard, encryption algorithm, key pair, private key, ciphertext, and decoding algorithm are the six essential components of a public-key cryptosystem. It simply encrypts with one key and decrypts using a slightly separate key.

It is possible to send the encrypted message once it has been created. Based on the keys in use at the moment, the block cipher will yield a different result. Updating the key alters the computation output.

It is possible to send the ciphertext once it has been created. Using a decoding method and then the same key which was used for encrypting, the ciphertext may be converted back to its original plain data upon receipt.

Main Differences Between Conventional and Public Key Encryption

  1. The conventional key requires only one key throughout the entire cryptosystem whereas public-key encryption requires two keys.
  2. In conventional encryption, one key can be utilized twice for encryption and decryption whereas in public-key encryption one key cannot be interchanged with the other’s role ie: one key is used for encryption and the other to decrypt.
  3. Conventional encryption is traditional and old whereas public key encryption is a modern cryptographic model.
  4. Conventional encryption is less secure than public-key encryption.
  5. Conventional encryption is symmetric whereas public key encryption is asymmetric in nature.


Encryption’s fundamental goal is to provide privacy, secrecy, and authenticity as well as anonymity. However, one of the main advantages of a public-key encryption method is that it is far simpler to provide valid shared keys than it is to distribute hidden keys, as is the case with traditional data encryption. However, public-key crypto algorithms are far slower than their traditional equivalents. As a result, these methods are primarily utilized for asymmetric encrypting data and encrypting tiny data items such as card numbers and PINs.

However, both are reliable types of cryptosystem models that are used in modern days for various secured purposes throughout organizations.


  1. https://www.khanacademy.org/computing/computers-and-internet/xcae6f4a7ff015e7d:online-data-security/xcae6f4a7ff015e7d:data-encryption-techniques/a/symmetric-encryption-techniques#:~:text=Vigen%C3%A8re%20Cipher,it%20%E2%80%9Cunbreakable%E2%80%9D%20in%201868.
  2. https://www.cloudflare.com/en-in/learning/ssl/how-does-public-key-encryption-work/
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