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Cryptography In Blockchain - Types, Benefits And Limitations

Cryptography serves as a means to protect data from unauthorized access. Within the blockchain, it is employed to ensure the security of transactions occurring between two nodes within the network. Cryptography in blockchain plays a pivotal role in ensuring the integrity and confidentiality of data through the use of complex algorithms that encrypt and decrypt information.

Author:Stefano Mclaughlin
Reviewer:Camilo Wood
Feb 22, 20242.3K Shares36.2K Views
Cryptography is a way to keep information safe from people who shouldn't have it. In blockchain, deals between two nodes are kept safe with cryptography. Cryptography and hashing are the two main ideas behind blockchain, as was already said. With cryptography, messages in the P2P network are kept safe, and hashing helps keep block information safe and links blocks in the blockchain together.
The main goal of cryptography is to keep things like people, events, and money from being spent twice. Cryptography in blockchainhelps to keep different Bitcoin events safe. It makes sure that only the right people can get, read, and work with transaction information.

What Is Cryptography In Blockchain?

Cubes Placed In Shape
Cubes Placed In Shape
A method or protocol called cryptography keeps information safe from outsiders while it is being sent. The word comes from two Greek words: Graphein, which means "to write," and Kryptos, which means "hidden."
  • Encryption- Changing data to a string of random bits.
  • Key- An encryption algorithm's key is a certain amount of information that is needed to get that information.
  • Decryption- the opposite of encryption, which turns a random string of bits into plain text.
  • Cipher - A mathematical function, also known as a cryptographic method, that changes plaintext into ciphertext, which is a random string of bits.

Features Of Cryptography

  • Only the intended recipient of the information is able to see it on a blockchain.
  • You can't add new information without being noticed while the old information is being saved or sent between the sender and the recipient.
  • The person who creates and sends information cannot later change his mind about wanting to send information.
  • The names of both the sender and the receiver are checked. The information's source and location are also checked.

Types Of Cryptography In Blockchain

Symmetric Cryptography

A secret code, also known as a cipher, is used to turn given information into a cipher in this type of cryptography. Here, both the sender and the receiver use the same key to secure and decrypt the message.
It was the first cryptography ever used. It is known that this method is easy to understand and can quickly handle data. The other type of cryptography is used to make sure that encryption keys are correct, as we will see next.

Asymmetric Cryptography

For Asymmetric Cryptography to work, the sender and receiver must each use a different key to secure and decrypt the message. Two keys the public key and the secret key work together to send the data with this method.
A public key is used to encrypt the information while it is being sent, and a private key is used to decrypt it. The same goes for adding a set of digital signatures with private keys. Anyone online can use their public key to decrypt it.

Cryptographic Hashing

Third, "Hashing" is a type of cryptography. Using cryptographic methods, any plain text can be turned into a cryptographic hash, which is a unique string of data. When you send data through cryptographic hashing, it can't be received again.
This makes it more important than the first two cryptography methods. There is another way to use hashing to reduce a large amount of data: it can be used to turn it into a short string of text.
Blue Cubes Connecting
Blue Cubes Connecting

Cryptographic Components In Blockchain

Hash Functions

A big part of blockchain technology is hash functions. They can take any size input and return a hash, which is a fixed-length string of letters.
Hash functions are one-way, which means that it is not possible to use computers to get back to the original input from the created hash. This property makes sure that the data saved on the blockchain is correct.

Digital Signatures

Digital signatures are a type of encryption that makes sure that something is real and can't be changed in a blockchain. A mix of public and private key sets is used to make sure that transactions are real.
The sender's private key is used to create a digital signature, and the recipient's public key can be used to check it. This makes sure that the message or transaction came from the sender and wasn't changed while it was being sent.

Symmetric And Asymmetric Encryption

A key part of keeping private data safe in the blockchain is encryption. Asymmetric encryption uses two keys that are mathematically linked: the public key and the private key.
Symmetric encryption uses a single shared key for both encryption and decryption. Asymmetric encryption is often used to share keys, set up safe routes, and keep information private in the blockchain network.

Merkle Trees

Merkle trees, which are also called hash trees, are types of data structures that are used to quickly check that large amounts of data saved in the blockchain are correct and consistent.
They use hash functions to create hash numbers for each piece of data, which are then put together to make a tree-like structure. Merkle trees make it possible to quickly check certain bits of data without going through the whole blockchain. This improves both speed and security.
Blocks Of 1 And 0
Blocks Of 1 And 0

Benefits Of Cryptography In Blockchain


Cryptography in blockchain protects the information saved on the blockchain by encrypting it. Every exchange and piece of data is encrypted, which makes it very hard for people who aren't supposed to be there to see or change the data. This makes sure that sensitive data kept on the blockchain stays private and safe.


Cryptography is a key part of making sure that the data on the blockchain can't be changed. With tools like cryptographic hashing, each block in the blockchain is securely connected to the one before it. This makes it almost impossible to change past transactions without invalidating the whole chain. This maintains the data's integrity and makes it hard to change.


Cryptography is a strong way to protect blockchain systems. It lets you make digital signatures, which are used to make sure that deals are real and that people on the network are who they say they are. Additionally, cryptographic methods are used to keep data safe while it is being sent and stored, preventing fraud, unauthorized access, and cyberattacks.


Even though it's not a direct result of cryptography, improvements in cryptographic methods like homomorphic encryption and zero-knowledge proofs help blockchain networks become more scalable. These methods make transaction handling faster and safer, which means that blockchain systems can handle more transactions without giving up security or decentralization.


Cryptography makes sure that blockchain transactions can't be disputed. This means that once a network member has digitally signed a transaction, they can't later say they weren't involved.
Cryptographic algorithms create digital signatures that can't be changed. These signatures are proof that transactions came from and are real, which builds trust and accountability in the blockchain environment.

Prevention Of Hackers

Cryptography is a very important part of keeping blockchain systems safe from hackers. Blockchain networks can effectively stop hacking attempts and keep private information safe from being accessed, changed, or stolen by people who aren't supposed to be encrypting data, securing transactions with digital signatures, and using strong cryptographic protocols. Overall, this makes blockchain systems safer, which gives users and stakeholders more faith in them.
Blockchain Technology and Scrabble Letters
Blockchain Technology and Scrabble Letters

Limitations Of Blockchain Cryptography

Difficult Access To Information

To keep data and transfers safe, blockchain cryptography often uses complicated algorithms and cryptographic methods. Even though this ensures high security, it can make it hard for people who aren't experts in cryptography to access and understand the information saved on the blockchain.

High Availability

The goal of blockchain networks is to provide high availability, which means that the network is always available and working. However, this level of availability usually requires a lot of infrastructure and resources, which can be pricey and hard to keep up, especially for smaller organizations or networks.

No Protection Against Vulnerabilities

Even though blockchain technology has strong security features, it can still be broken. Attackers may be able to find flaws in cryptographic protocols and algorithms that can be used to break security or get to private data without permission.


It can be pricey to set up and run blockchain networks because of things like hardware costs, energy use (especially in proof-of-work consensus methods), development costs, and ongoing running costs. Also, strong cryptographic measures that protect the network's security usually cost a lot of money.


Even though blockchain systems use strong cryptography to protect themselves, they can still be attacked and threatened in different ways. These flaws might result from issues with the cryptographic algorithms themselves, implementation errors, or social engineering attacks on people who have private data or cryptographic keys stored on the blockchain.
Blockchain Applications Analysis
Blockchain Applications Analysis

Hash Functions In The Blockchain

Hash functions are one of the most common types of cryptography algorithms. They take any input data and return a string of a set length, no matter how big or short it is. A word, a sentence, a longer piece of text, or even a whole file can be used as input. A hash is the output that is made from the raw data and has a fixed length.
There are a lot of different secure hash functions and algorithms, such as MD5, BLAKE2, SHA-1, SHA-256, and many more. SHA-256, which stands for Secure Hashing Algorithm 256, is one of the most well-known secure hash functions that is used a lot in blockchain technology.
It creates a hash against the message we give it when we use the hash method. The hash algorithm always returns a string of a set length, no matter how big the letters or numbers are that you enter. Based on the hash method, the fixed-length output could be 32 bits, 64 bits, 128 bits, or 256 bits. As an example, SHA-256 creates a hash number that is 256 bits long, which is the same as 64 characters.
Anyone trying to decrypt the hash won't be able to tell how long or short the input is just by looking at the length of the output if you use a fixed-length output. We can only get to the original string from its hash by using "brute-force."
To use brute force, you have to pick random inputs, hash them, and then compare them to the goal hash. If the SHA-256 hash method is used, for example, a brute-force attack would have to try 2^256 times to make the first piece of data.

FAQs About Cryptography In Blockchain

What Is The Meaning Of Cryptography?

Cryptography is the practice and study of techniques for secure communication.

Do All Blockchains Use Cryptography?

Yes, all blockchains use cryptography for security.

What Are The Objectives Of Cryptography In Blockchain?

The objectives of cryptography in blockchain are privacy, integrity, authentication, and non-repudiation.

Which Cryptography Is Used In Bitcoin?

Bitcoin uses cryptographic algorithms such as SHA-256 for hashing and ECDSA for digital signatures.


Blockchain technology is one of the main areas of development for all multinational businesses. In the past few years, a huge number of startups have also sprung up around this technology.
While blockchain hasn't been widely used yet, there are many job opportunities for professionals to explore and grow in this field. Cryptography in blockchain is one of them. Over time, this field will be full of possibilities. To prepare for this, you can start learning about blockchain technology.
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Stefano Mclaughlin

Stefano Mclaughlin

Camilo Wood

Camilo Wood

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