The term cryptography comes from the Greek words 'Kryptos' and 'Graphein' which mean 'Secret' and 'Writing'.
Cryptography is the process of changing a message to hide its meaning. Meanwhile, cryptography creates or produces written messages so that the message or information remains confidential.
Cryptography is a concept that is commonly used in information security systems at various levels. Information can only be read if there is a public key for the description process, which is the process of converting encrypted data to original data.
During the transmission and storage of information, message data will be kept confidential. This can be seen when there are many types of data messages and information to be sent and stored digitally, encryption can help protect data and information.
Additionally, cryptography outlines how the blockchain works and supports it to operate properly. Some functions defined in cryptography are useful for blockchain. Among them include 'signature' and 'hash'.
Signature or Digital Signature allows users to hide information with a secret key that will tell that the information belongs to a specific individual. As for cryptocurrencies, Digital Signatures are used to sign ledgers that allow users to prove ownership of the account they hold.
Hash on the other hand stores information, it takes long data and turns it into some random words, letters or numbers.
As already known, cryptocurrencies use public-key cryptography.
As an example situation, let's say you want to send one BTC to a friend. First, you need to use the private key which is the password to log in to the wallet.
Since your friend has given you a public key (wallet address), you will use it to encrypt the data and execute the transaction. Then when the transaction is confirmed, your friend will use the private key to access the funds in his wallet.
During the process, you and the recipient will generate a cryptographic hash by signing the transaction. The two hashes will be combined into a final signature, providing proof that the transaction has not been tampered with.
In a blockchain network, the same process will be used to verify transactions as well as generate new blocks. Now, malicious parties will have no way to break the public-key cryptographic technology underlying the blockchain network.
