What is a public and private key in blockchain?

Blockchain technology greatly relies on cryptography to ensure secure and transparent transactions. Public and private keys are central to the cryptographic infrastructure of blockchain.

Public key

A public key is a unique identifier that identifies an account in the blockchain network. It is used to receive funds and can be searched for in the ledger. The public key is publicly available, visible on the blockchain, and can be freely shared with anyone.

Private key

A private key is a confidential piece of information that should never be shared with others. The private key is like a digital signature and password. It helps ensure security and allows users to prove their identity and manage access to their assets and information on the blockchain network.

Private keys are securely stored in the digital wallets of blockchain participants. The security of private keys is very important, as anyone who knows a private key can access and control the associated digital assets.

Relationship between public and private keys

The relationship between public and private keys in blockchain is based on the principles of public key cryptography. The two keys are mathematically related, but the private key cannot be derived from the public key. Instead, the private key is used to generate a digital signature, which can be verified by anyone using the corresponding public key. Let's take an analogy of colors to see how this works.

In this analogy, the color blue represents the public key. It is agreed upon and known to both Emma and Liam. Similarly, in blockchain, the public key is used for encryption and can be shared with anyone.

Emma chooses a private color, red, which represents her private key. This private key is known only to her, just like a private key in blockchain. Likewise, Liam chooses a private color, yellow, which represents his private key. This private key is also known only to him.

Now, when they combine their private colors with the common color, it symbolizes the process of encryption. And then they exchange the resulting colors. In blockchain, this is similar to sharing encrypted data using public keys.

Just as mixed colors cannot be separated back into their individual components, encrypted messages cannot be reversed to retrieve the private key.

Finally, both Emma and Liam combine their private color (private key) with the received result and both of them end up with the same color. This demonstrates that their private and public keys have matched, enabling secure transactions using the common color as a foundation.

Significance of public and private keys in blockchain

In the blockchain ecosystem, public and private keys play fundamental roles in securing transactions and establishing digital identity.

Non-repudiation

One of the key benefits of using public and private keys in blockchain is non-repudiation. It means that once a transaction is signed with a private key, it can be proven that the sender is the owner of that private key, and they cannot deny having initiated the transaction. This property enhances trust and accountability within the blockchain network.

Authenticity of transactions

To verify the authenticity and integrity of a transaction, the sender uses their private key to generate a digital signature. This signature is a unique cryptographic representation of the transaction data. Other participants in the network can use the sender's public key to verify the digital signature, ensuring that the transaction has not been tampered with and originates from the claimed sender.

Identity verification

Public and private keys are utilized in identity management within the blockchain. By associating a public key with a specific user or entity, participants can establish a verifiable digital identity. Transactions and interactions can be traced back to the corresponding public key, enabling transparency and accountability.

Conclusion

Public and private keys are very important for keeping blockchain technology secure. Public keys are like addresses that let us encrypt and check transactions. Private keys are secret keys that let us unlock data and make digital signatures. By using these keys, blockchain networks make it possible for people to interact safely without needing to trust each other.