Decryption

What Is Decryption?

Decryption is the act of undoing an encryption process so that formerly encrypted data can be viewed or accessed. It entails converting unreadable data (ciphertext) into readable data (plaintext). Decryption is the method of transforming encrypted information back to the original and comprehensible form, whereas encryption is the method of making data unreadable. This method of encrypting and decrypting data is based on a certain type of cryptographic key.

Encryption Depends on Cryptographic Keys

Cryptographic keys are often represented as a string of numbers and letters created by cryptographic algorithms. Using the correct decryption key, encrypted data can be simply transformed back to its original form. 

Decryption becomes significantly more difficult without the correct key and can only be accomplished by brute-force attacks. On the other hand, strong encryption techniques generate nearly impossible keys to crack. 

All symmetric and asymmetric encryption employ cryptographic keys. The techniques are classified into two broad groups based on how keys are generated and used: symmetric key cryptography and public key cryptography (PKC).

Background of Encryption 

In symmetric key cryptography, the very same key is used for the encryption and decryption of data. Before 1976, this would be the only type of encryption technology known. Public key encryption (or asymmetric encryption), on the other hand, employs a pair of mathematically related keys. A pair of keys like this comprises a public and a private key. The public key is used to encrypt data, whereas the private key is required to decrypt it.

Cryptographic Algorithm

Cryptographic algorithms use plaintext to generate encrypted data, which is then sent back to be decoded. For example, the Elliptical Curve Digital Signature Algorithm is used for encryption and decryption on the Bitcoin network (ECDSA). 

Cryptographers are concerned about the security of their cryptographic systems. Algorithms are meant to be practically hard to crack by a real adversary. Some algorithms are known as information-theoretically secure, which means they can be demonstrated to be impenetrable even with theoretically infinite computing power. 

However, in practice, these systems are incredibly difficult (sometimes impossible) to implement. As a result, many cryptographic systems in use today are computationally secure. Although breaking them is technically possible, it would be impractical for a bad actor to do just that.