What is Cryptography?

Before we start learning cryptocurrency, we need to have a basic knowledge of cryptography. Cryptocurrency was designed using the cryptography concept. Cryptography is formed from “crypt” and “graphy”. Crypt means secret or hidden while graphy means writing. Therefore,  cryptography could be defined as the act of sending secret messages.

The cryptography concept has been in existence for a very long time before the creation of computers. Its existence could be traced back to the era of slavery when secret messages were written on the head of the slaves. However, this method of sending secret messages could be hacked by shaving the hair of the slave. The cryptography concept has been evolving over time so as to outsmart hackers. This means that a method that is safe today may no longer be safe tomorrow.

Cryptography makes the internet safe and secure. The adoption of cryptography on the internet makes your personal information secure. Your banking details are also safe and it makes it very difficult to easily hack into your account.

Cryptography uses mathematical terms that most people do not understand. Some of the terms used in cryptography and their simple meaning are:

The Hash (with the symbol #): This is a process where the input messages are protected from hackers by converting them into long strings of letters and numbers. The output would look like a piece of garbage because it will be totally meaningless. The word “hashing” means chopping and mixing. This indicates that the messages are chopped and mixed or hashed to form an entirely different thing. In the hashing process, the receiver would receive the original message that was transferred from the sender.

Encryption: This is the process of scrambling the message into unreadable text. The scrambled text is called the cipher text and it will be decrypted ( translated) by the receiver using the key generated by either the sender or the receiver before the communication process began. It is only the sender and the receiver of the information that have the key to decrypt it.

Cryptography is essentially the science of encryption and decryption of information that is being initiated by the sender and the receiver.

The basis of Cryptography
Encryption: This employs an algorithm (a set of rules) to scramble or juggle up the information or the plain text using the encryption key. For instance, if the plain text is uptrendfinancialsignal, it could be scrambled to langislaicnanifdnertpu using the encryption key. The information becomes unreadable, just like what was explained earlier

Decryption: This is simply reversing the encryption to make the information readable again. The information becomes plain text after decryption. This method was used by Julius Caesar, a general in the Roman Empire, to pass across confidential information.


Ciphers and Cipher Text

Ciphers: The Cipher is an algorithm (a set of rules) that makes the information unreadable.

Cipher Text: This is the scrambled text and it is unreadable. This is what will be transmitted to the receiver to prevent being hijacked by attackers. The encryption key is being shared between the sender and the receiver. The receiver needs the encryption key to decrypt the Cipher text.

diagram showing encryption and decryption in cryptography

Application of Cryptography
It is used by a website to secure the user’s information. Without cryptography, your passwords would be exposed on the internet. Anyone on the internet network would gain access to your private information.

The cryptocurrency was launched on a blockchain that uses encryption algorithms and hashing to secure data. Blockchain technology uses cryptography to encrypt data in order to prevent third-party interference. In other words, it makes the data transmitted on the blockchain tamper-proof.

The army uses the cryptography concept to pass across confidential information. The army could encrypt the “ATTACK” message to be decrypted by the soldiers on the war front.


Types of Encryption in Cryptography
Symmetric Key Cryptography: In this type of encryption, the sender and the receiver have a single secret key. This means that the key is shared between the sender and the receiver of the data. The secret key must not be sent along with the Cipher text to avoid being hijacked in the process of data transition. The key must be kept private because the encryption key and the decryption key are the same. The major risk in this process is key sharing. The private key could be intercepted during the sharing process, thereby forfeiting the use of cryptography.

Asymmetric key cryptography: In this type of encryption, two keys are used- the private key and the public key. There is no exchange of keys, thereby eliminating the flaws in Symmetric-key Cryptography. The public key is used to encrypt the information or the plain text into cipher by the sender. The public key is known to everyone. The private key is used to decrypt the cipher text to plain text by the receiver. Only the receiver has access to the private key. For example, anyone could drop a letter in your mailbox (take this as the public key) but you are the only one that could open the mailbox (take this as the private key) to gain access to the information in the letter. The public key cannot be used to decrypt the cipher text.