What is cryptography? What are the benefits of cryptography to blockchain? Blockchain is a breakthrough technology that makes cryptocurrency possible. Without the security and recording ability of blockchain, cryptocurrency will have no real value, because anyone can create any amount of money they want. But you know what? Without cryptography, none of this would be possible. Cryptography is a super spy level technology that gives blockchain incredible power. So what is cryptography? Let's take a look.

What is cryptography?

Cryptography is a form of Internet security. This is the process of converting information into code (encryption), so that only the intended recipient can access the information. Encrypting data can protect information from potential hackers, who are known as "adversaries" in the field of cryptography.

How does encryption work? Use algorithms and keys to convert plaintext information into code or ciphertext. You can use the same key for many plaintext and ciphertext combinations. Hackers should not be able to find the original text or key.

You can use stream cipher to encrypt information, where each byte of the original text is encrypted one byte at a time. The length of the ciphertext is the same as the original text. You can also use a block password to encrypt all data blocks at once.

What are the types of cryptography?

symmetric cryptography

Symmetric cryptography - or symmetric key cryptography - is the first encryption type used online. Symmetrical encryption converts information into a password or encryption code. To decrypt the password, you need a key.

In symmetric cryptography, both sender and receiver use the same key to encrypt and decrypt data. Because it is very simple, symmetric encryption can process large amounts of data very quickly.

However, as you can imagine, shared keys have become a problem. Think about when you tried to share a password with someone. If you send the password via SMS or email, hackers can easily see it. Your password almost needs a password!

Similarly, sharing keys from the sender to the receiver can cause vulnerabilities that hackers can exploit quickly.

This is where the following types of cryptography can be used: asymmetric cryptography.

asymmetric cryptography

With asymmetric encryption, the sender and receiver have different keys. One key is used to encrypt the information, and the other key is used to decrypt the information at the other end.

However, if two people have different passwords in essence, how can you ensure that only the correct receiver can open the message when it is sent? In short, if you don't share the key, how do you tell the code to open it for the right person?

To solve this problem, asymmetric cryptography uses a system where each user has two keys: public key and private key. Your public key is unique to you, but others can also see it. Nobody knows your private key except you. This is like the PIN code of your bank account.

Public and private keys work together. Therefore, in the transaction, the person who sends the information can send it to your public key. Then, in order to decrypt the data sent to your public key, you must have a private key to unlock it.

To send a message to someone, you can encrypt it using their public key. Then, only they can use their private key to unlock it. Or, if someone uses their private key to add a digital signature to a group of data, anyone online can use their public key to decrypt the signature and verify whether it is really them.

Cryptographic hash

The last kind of cryptography is hash. An encrypted hash is a set of text. Any plaintext information can be converted into a unique text string through the hash algorithm. Words have no meaning. For example, the word "Hello" can become a sha1 hash: "f7ff9e8b7bb2e09b70935a5d785e0cc5d9d0abf0".

Once the original data passes the encryption hash function, you cannot reverse the process. This is the difference between encryption hash and symmetric or asymmetric encryption, which can be decrypted with a key. There is no way to start from a hash you have never seen before and deduce what the original data is.

As long as the same hash algorithm is used, the same data will always become the same hash. Therefore, if the data along the way changes, users can judge by comparing it with the final hash. However, hackers have found ways to obtain a large number of hash values, and then compare them with the hash values of common words and phrases. If they find a match, they know what the hash represents. This is how hackers steal passwords in data disclosure.

Another basic feature of a hash is that you can reduce a large amount of data to a small piece of text in the hash. Hashes are always the same length, no matter how long or how wide the data is. Therefore, hash is a method of compressing information. We will explain in detail why this is so important, but first, let's introduce blockchain.

What are the benefits of cryptography to blockchain?

security

Cryptography is the key to blockchain ledger security. Each transaction is recorded on the blockchain using encrypted data. Each user can use their public and private keys to access their own information and securely buy and sell cryptocurrency.

Through encryption hash, the blockchain records the root hash, in which each transaction is securely encoded. If someone tries to tamper with the data of any part of the blockchain, the change will result in a completely different hash in the root hash. By comparing the root hash with the root hash on their own computer, other users can see that the data has been leaked.

Scalability

Encrypted hashes allow unlimited transactions to be recorded securely on the network. Because multiple transactions can be combined into a hash, blockchain can continue to grow on a large scale.

reliability

The encrypted hash is irreversible, so no one can cancel the transaction. This process protects them from any hostile actions and ensures that all users can rely on the accuracy of the digital ledger.

In general, the above content introduces in detail what cryptography is and what benefits cryptography brings to blockchain. I believe you will understand after reading it. In short, cryptography technology is the foundation of building blockchain. Cryptography provides us with tools to encrypt, securely send cryptocurrency and record transactions over time. It allows us to securely trade cryptocurrencies without any centralized authority, and it ensures that blocks will continue to be added to the chain without restriction.