What is Encryption?

Encryption is everywhere: from protecting your passwords to securing your bitcoin. It ensures that sensitive information stays private, even in a world where data flows freely across the internet. But what is encryption really, and how has it evolved?

The Basics of Encryption

Encryption basically scrambles readable data (plaintext) into something incomprehensible (ciphertext). Only someone with the right key can turn it back into its original form. This process is essential for privacy, whether you’re sending a message, logging into your account, or securing your Bitcoin wallet.

Good encryption doesn’t just make data look confusing, it makes it nearly impossible to unscramble without the right decryption key, even if you intercept the message.

From Caesar to Codebreaking Computers

Humans have used encryption for thousands of years. Ancient ciphers like the Caesar Cipher used simple substitution tricks (swapping letters in predictable ways). But once attackers figured out how to analyze letter frequency (like spotting that “E” appears most often in English), these ciphers quickly became easy to break.

As communication and warfare evolved, so did cryptography. The 20th century saw huge leaps forward, especially during World War II. Devices like the Enigma machine encrypted military messages with constantly shifting keys. But those too were eventually cracked—famously by Alan Turing’s early computers using brute force, testing every possible combination until the right one was found.

Digital Encryption

After the war, encryption moved from military secrets to protecting business data. IBM’s Data Encryption Standard (DES), adopted in the 1970s, became the U.S. government standard. But DES only used 56-bit keys. They could be broken by brute-force attacks, even with modest computing power.

To extend its life, the industry shifted to “Triple DES,” applying the encryption three times. But this was a patch, not a fix.

The Rise of AES

In 2001, DES was officially replaced by the Advanced Encryption Standard (AES). AES uses up to 256 bits and remains widely used today. It powers the encryption behind Bitcoin wallets, encrypted messaging apps, and even secure websites.

While AES is used for encrypting and decrypting data using a secret key, the in the Bitcoin space well known SHA-256 often works alongside it to enhance security. SHA-256 is a cryptographic hash function that generates a fixed 256-bit output, commonly used to create or verify keys. In many systems, a password or passphrase is first hashed using SHA-256 to produce a secure and consistent key, which is then used by AES for encryption.

The Breakthrough of Public-Key Cryptography

Before the 1970s, encryption had one big problem: you had to safely share your decryption key with anyone you wanted to communicate with. That’s risky. But in 1976, Whitfield Diffie and Martin Hellman changed the game.

They introduced asymmetric (public key) cryptography: one key for encryption, another for decryption. You can share your public key freely, and only your private key (kept secret) can unlock the message. This model forms the basis of secure email, HTTPS websites, and how Bitcoin handles signatures and transactions.

Encryption becomes a human Right

In the Cold War era, governments treated strong encryption as a weapon. Export was restricted, and high-level cryptography was mostly reserved for the military. That changed in 1991 when Phil Zimmermann released PGP (Pretty Good Privacy), giving the public access to powerful, open-source encryption.

Since then, encryption has become a battleground. Governments often demand “backdoors” under the guise of public safety, while cryptographers fight to keep privacy intact for all users.

Final Thoughts

• Encryption transforms readable data into protected code that only specific parties can unlock.
• Strong encryption is essential for privacy in everything from emails to Bitcoin wallets.