Cryptography, at its core, is the practice of using algorithms to convert regular messages (referred to as “plaintext” in cryptography) into seemingly meaningless gibberish (known as “ciphertext”). This process relies on an additional piece of information known as “the key” to decrypt the ciphertext back into readable plaintext. The main objective of cryptography is to ensure that the information being transmitted remains secure and inaccessible to unauthorized individuals or third-party adversaries.
In the early stages, cryptography primarily focused on the utilization of ciphers, which were algorithms employed to encrypt and decrypt messages. These ciphers, commonly referred to as classical ciphers, could be manually encoded and decoded. However, they were not robust enough to withstand the cryptanalysis techniques available during that time.
The emergence of radio and internet communications necessitated the development of stronger encryption methods. With messages being transmitted indiscriminately, there was an increased risk of interception. To address this concern, computers introduced advanced and highly secure techniques for scrambling plaintext. 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 the resources available to adversaries.
Presently, cryptography plays a vital role in computer communication. It is extensively utilized in various applications, including the implementation of cryptographic hash functions like SHA-256. This specific hash function plays a critical role in safeguarding the operations of Bitcoin (BTC) and other cryptocurrencies.