Decrypting Cryptography: How Cryptography Keeps Your Data Safe

Amidst World War II, where knowledge was the deciding factor in determining victory, the Germans employed the renowned Enigma machine, utilizing the science of cryptography to encrypt their critical messages. As depicted in the film ‘The Imitation Game,’ the British, led by the brilliance of Alan Turing and his team at Bletchley Park, successfully decoded these messages. Their pioneering work ultimately played a crucial role in saving countless lives and turning the tide against Germany.

Cryptography, the science of secure communication, has evolved significantly since its wartime origins. In today’s digital age, it plays a pivotal role in safeguarding our sensitive information and ensuring the integrity of our communications. The principles of cryptography are embedded in the security of online transactions, communications, and data storage. As we navigate the vast landscape of the internet, cryptographic techniques are employed to protect our privacy and support the confidentiality of our data.

Let us investigate three concepts:

1. Encryption: This is the process of converting information into a code to prevent unauthorized access. It is like putting a message into a secret language that only those with the key can understand.
2. Decryption: On the flip side, decryption is the process of converting coded or encrypted data back into its original form. It is the key to unlocking the secret language and making sense of the information.
3. Keys: Think of keys as the secret codes that facilitate the encryption and decryption process. They are the linchpin of cryptographic operations, ensuring that only authorized parties can access the information.

A “Key” example

Picture yourself as a soldier. To communicate securely with your troops, you need to ensure your messages are confidential, untampered, and authenticated. These principles are known as the CIA triad—Confidentiality, Integrity, and Authentication. Now, let’s craft our own cryptographic machine for the ultimate security.

Confidentiality:

To ensure no one can read the message, let us encrypt it using Caesar’s cipher. It is named after Julius Caesar, who reportedly used it to secure military communications. It involves shifting each letter in the alphabet by a fixed number of positions determined by a key.

Message: THE BRITISH ARE SPYING ON US

Key: 3

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Our enciphered message would be: WKH EULWLVK DUH VSBLQJ RQ XV

Looking at the message above, notice that without the key the message is unreadable and cannot be understood by someone without the key.

Integrity:

Now we need to make sure that no one can tamper with the message. To do so, we could use something called a hash function.

We first assign all the letters a numerical value based on their place in the alphabet. The hash would be a sum of these:

A	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q	R	S	T	U	V	W	X	Y	Z
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26

The hash would be equal to the sum of the numerical value of each letter.

THE BRITISH ARE SPYING ON US = 20 + 8 + 5 + 2 + 18 + 9 + 20 + 9 + 19 + 8 + 1 + 18 + 5 + 19 + 16 + 25 + 9 + 14 + 7 + 15 + 14 + 21 + 19 = 274

274 would be the result of our hash function. If the content of the message is changed, the hash would also change hence, integrity of the data. This will then be appended to our encrypted message to ensure that its content is not changed.

Authentication:

But how can your soldiers be certain it’s you who sent the message? We could do this by signing it. Craft a signature that no one can duplicate and affix it to your message. This way, your troops know it’s you who sent them the message. Like handwritten signatures, a digital signature is a unique identifier made using cryptographic techniques. It ensures that the sender is who they claim to be and verifies the integrity of the message.

Voilà! You’ve just fashioned your personal crypto contraption. However, for the sake of global harmony and humanity, we strongly advise against employing it for personal warlike endeavors.

These simple techniques are the underlying methods of how our everyday messages and data are being encrypted. Of course, with the computing power of computers today, we use more complex and advanced cryptographic techniques.

Do you have a software project that requires sensitive and high standards of security? Or do you want to implement cutting-edge technologies into your project? Connect with us at Datahouse, a team of enthusiastic, highly skilled experts here to help you convert your software ideas into reality.