Cryptography means secret writing, defined as a branch of cryptology that deals with encryption or coding techniques designed to modify linguistic representations with the ultimate goal of making them incomprehensible to unauthorized recipients. The objective of cryptography is to protect information so that the intended recipient is the only one capable of understanding the information sent. A key or coordinate may exist that allows the decoding of this information; for this purpose, there are encryption methods or systems known only to the recipients. Cryptography originated in times of war due to the need to send strategic messages that are key and that opposing factions are unable to understand (you can delve deeper into the development of this in the film The Imitation Game, starring Alan Turing during World War II). Currently, cryptography is primarily handled by areas of computer science with the aim of protecting the security of data or communications shared mainly on the internet.

Web Cryptography

In addition to protecting information transmitted over the internet, cryptography preserves the security of users\' communications and operations. This includes account passwords: well-known cases of SQL injection allowed users\' passwords to be compromised; video calls, such as the case where Zoom did not encrypt its connections, thus compromising user privacy; and banking transactions: the case of early versions of Mercado Pago in Chile, where bank card details, expiration dates, and CVV verification codes were exposed to third parties. Given the need for encrypted communications, Google implemented SEO guidelines to prioritize websites that comply with encryption standards using HTTPS protocols. Furthermore, cPanel implemented Let\'s Encrypt plugins for free SSL integration. Let\'s remember that just a few years ago, implementing these protocols required dedicated IPs and the purchase of a certificate (not insignificant costs), in addition to implementation and adaptability costs. All these practices have fostered the development of cybersecurity fields. What today seem like mere steps in development were once deliberate implementations by expert cybersecurity engineers.

Types of Cryptography

Depending on how messages are encrypted, they can be classified mainly in two dimensions:

Symmetric Cryptography

Symmetric cryptography uses the same key to encrypt and decrypt messages, so that both parties have the key or coordinate to decrypt it.

Asymmetric Cryptography

This method uses two keys: public and private. The public key is accessible to anyone, while the private key is only held by the owner of the key.