A private key, as the name suggests, is a randomly generated number that is kept secret and held privately by its users.
Private keys need to be protected and no unauthorized access should be granted to that key; otherwise, the whole scheme of public key cryptography is jeopardized, as this is the key that is used to decrypt messages.
A Complete Guide to Understanding This Blockchain Concept
Private keys can be of various lengths depending on the type and class of algorithms used.
For example, in RSA, typically a key of 1024-bits or 2048-bits is used.
The 1024-bit key size is no longer considered secure, and at least a 2048-bit key size is recommended.
A public key is freely available and published by the private key owner.
Anyone who would then like to send the publisher of the public key an encrypted message can do so by encrypting the message using the published public key and sending it to the holder of the private key.
No one else is able to decrypt the message because the corresponding private key is held securely by the intended recipient.
Why This Matters for Blockchain Technology
Once the public key encrypted message is received, the recipient can decrypt the message using the private key.
These include authenticity and identification of the publisher of the public keys.
In , two examples of asymmetric key cryptography: RSA and ECC.
RSA is the first implementation of public key cryptography whereas ECC is used extensively in blockchain technology.
Key Points to Remember
- Public and private keys A private key, as the name suggests, is a randomly generated number that is kept secret and held privately by its users.
- Private keys need to be protected and no unauthorized access should be granted to that key; otherwise, the whole scheme of public key cryptography is jeopardized, as this is the key that is used to decrypt messages.
- Private keys can be of various lengths depending on the type and class of algorithms used.
- For example, in RSA, typically a key of 1024-bits or 2048-bits is used.
Going Deeper: Advanced Concepts
RSA RSA was invented in 1977 by Ron Rivest, Adi Shamir, and Leonard Adelman, hence the name Rivest–Shamir– Adleman (RSA).
This type of public key cryptography is based on the integer factorization problem, where the multiplication of two large prime numbers is easy, but it is difficult to factor it (the result of multiplication, product) back to the two original numbers.
The crux of the work involved with the RSA algorithm is during the key generation process.
An RSA key pair is generated by performing the following steps: 1.
Conclusion
Public and private keys represents one of the many innovative layers that make blockchain technology so powerful and transformative. As distributed systems continue to evolve, a solid understanding of these core concepts becomes increasingly valuable — not just for developers, but for anyone building, investing in, or working alongside blockchain-powered systems.
Whether you are just starting your blockchain journey or deepening existing expertise, mastering these fundamentals gives you the tools to think clearly about decentralized systems and make smarter decisions in this rapidly evolving space.