Asymmetric Encryption Algorithms or Public key Algorithms
what is asymmetric algorithm and how it’s work?
Public-key algorithms are asymmetric algorithms based on the use of two different keys, instead of one.
- Private key — This key must be known only by its owner.
- Public key — This key is known to everyone (it is public).
The key used for encryption is different from the key used for decryption.
Either key can be used for encryption, but the complementary matched key is required for decryption.
- If a public key encrypts data, the matching private key decrypts data.
- If a private key encrypts data, the matching public key decrypts data.
Public-key systems have a clear advantage over symmetric algorithms. There is no need to agree on a common key for both the sender and the receiver.
The usual key length is 512 to 4,096 bits.
How does public-key cryptography work?
Method 01 — A encrypt message using B’s Public key.
Authenticity — ❌
Integrity — ❌
Confidentiality -✅
Non-reputation -❌
Method 02 — A encrypt message using A’s Private key
Authenticity — ✅
Integrity — ✅
Confidentiality -❌
Non-reputation -✅
usage: — News web sites.
Method 03 — A encrypt message using A’s Public key.
No use
In a PKC scheme, the public key is used by a sender to encrypt information, while the private key is used by a recipient to decrypt it. Because the two keys are different from one another, the public key can be safely shared without compromising the security of the private one. Each asymmetric key pair is unique, ensuring that a message encrypted using a public key can only be read by the person who possesses the corresponding private key.
- A sender and receiver do not share a secret key.
- These algorithms are relatively slow because they are based on difficult computational algorithms.
Eg: — RSA, ElGamal, elliptic curves, and DH.
Applications of public-key cryptography
prominently in blockchain and cryptocurrency technology. When a new cryptocurrency wallet is set up, a pair of keys is generated (public and private keys). The wallet address is generated using the public key and can be securely shared with others. The private key, on the other hand, is used for creating digital signatures and verifying transactions, and therefore, must be kept in secret.