Blockchain is a growing list of records, called blocks, which are linked using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp, and the transaction data.
The PKI accomplies two functions - authentication and the message privacy through encryption/decryption mechanism.
The most popular PKI algorithms are RSA and ECDSA.
In Blockchain a hash function maps the data of any arbitrary size to data of fixed size.
The blocks created by various miners are chained together to form what is known as a truly distributed public ledger.
Nonce is a number such that the block's hash meets a certain criterion. This criterion could be that the generated hash must have its leading four digits to be zero.
Root Hash includes the hashes of all the transactions within the block, these transactions may be pruned to save the disk space.
An open blockchain network has no central authority. Since it is a shared and immutable ledger, the information in it is open for anyone and everyone to see.
Following are the key pillars of blockchain:
Public Key Cryptography or in short PKI is also known as asymmetric cryptography. It uses two pairs of keys - public and private. A key is a some long binary number. The public key is distributed worldwide and is truly public as its name suggests. The private key is to be strictly held private and one should never lose it.