Cryptography has a long history, initially focusing on ciphers, which were algorithms used to transform regular messages (known as “plaintext”) into seemingly unintelligible text (known as “ciphertext“).
From Ciphertext and Keys to Cryptanalysis
To transmit these messages, the receiver would employ an additional piece of information called the “key” to decrypt the ciphertext back into readable plaintext.
Limited Encryption in Early Cryptography
Early ciphers, such as substitution and transposition ciphers, collectively known as classical ciphers, could be encrypted and decrypted manually.
However, they did not provide sufficient scrambling of information to withstand the cryptanalytic techniques available at that time.
Securing Data in the Computer Age
With the rise of computers, new and highly secure methods of encrypting plaintext emerged.
While it is theoretically possible to decipher an advanced encryption algorithm without a key, it is practically infeasible to do so within a reasonable timeframe using available resources.
From SHA-256 to Cryptocurrencies
Today, cryptography is a fundamental aspect of computer communication.