Cryptography From a Dummy

in LeoFinance8 months ago


Crypto here, crypto there, everywhere there is crypto. As of the moment, every time I hear or read the word crypto it will definitely be related to cryptocurrencies. Yeah, that's because I am now also a resident of the crypto realm. But let's just look a bit closer and try to put light on an aspect that makes our beloved cryptocurrencies a possibility.


Cryptocurrency and its technologies heavily rely on cryptography. But what in the fresh hell is cryptography? Cryptography is the science of transforming a piece of information into a secure format. At least that's the technical definition of the word. The process involved in cryptography is encryption. Encryption transforms an input, let's say the message "I LOVE YOU", into an unreadable format "01101001 00100000 01101100 01101111 01110110 01100101 00100000 01111001 01101111 01110101".

In this case, I just translated "i love you" into binary code, which is fairly unreadable to an average user. Although technically, this is just a translation, this can also be considered "encryption" because the input text "I love you" is transformed into something that is fairly unrecognizable.


In another case, we can transform the input text which is "I love you" into "r uxen hxd". Now that seemed to be really encrypted since there's no language in the human language that has those words.

After a message is encrypted or transformed, it is now ready for sending. While the message is in transit, no one can understand or read it because they are not the intended recipient. But what would make the intended recipient different and special from others?

The intended recipient has the magic to transform back the encrypted message into the raw plaintext format, this process is called decryption. Using a key, the recipient of the message can transform "01101001 00100000 01101100 01101111 01110110 01100101 00100000 01111001 01101111 01110101" and "r uxen hxd" back to "i love you". Then the secure transfer of information and communication has been done. And that's cryptography.

Caesar Cipher

This is one of the earliest practices of cryptography. It's attributed to Julius Caesar who devised a plan to send messages to his constituents without the messengers knowing what the contents of the messages are.

He transposed the letters of the original message in several places. For example, the letter A becomes C, the letter B becomes D and the old letter C becomes E.

That's the way "i love you" became "r uxen hxd". But instead of moving two places in the alphabet, we moved 9 places. Now that transposition or shift of letters is called the "cipher key". If you knew that the cipher key for "r uxen hxd" was 9→, then you could have deciphered the text into "i love you".

Modern Cryptography

Nowadays, we use and rely on cryptography every single day. When you send a text on your smartphone, cryptography is involved. When you withdraw money from the ATM, cryptography is involved. Basically, in everything where information is needed to be secured, cryptography is used. But instead of the simple cipher, cryptography in the modern days uses more advanced technologies such as hashing.


Hashing is the process wherein cryptographic hash functions(CHF) are used. CHF transforms an input with an arbitrary size into an encrypted value with a fixed size. In our example above, the "I love you" message may turn into 364897656. If we change the input into "love" the message may turn into 987456125. Even just a little deviation from the input will result in a tremendous change in the encrypted hash.

Notice that our inputs are not the same length when it comes to letter compositions (size), but their results are both the same length (size), which is in this case, 9 characters. That's the power of hashing. There's no way to guess what the original message is just from the encrypted text, unlike from "r uxen hxd" which has the same letters as "i love you".

The bitcoin network uses hash technology too. Secure Hash Algorithm or SHA. An encrypted information using SHA (SHA-256 in particular) looks like this : 4c9622e1148 0b855de50e62999d194039eb2faa9e715cc9d9ef604015aa1fe.


Cryptography is such a vast subject as we try to dive into it. So that being said, I'll just stop here for now. All the information that I was trying to learn about cryptography today is getting encrypted inside my brain and I think that I just swallowed all the keys needed to access them.


Hey there!

Thank you for being with me while I try to read up on this interesting topic. Although, I have to say, all of this information ugh. Makes me wanna hug my pillow and drop still on my bed. Anyways, thanks for your time and I'll see you in the next, as usual.


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