Blockchain is a technology that enables immutable records and cryptographic security on the network. Blockchain can store transactions and data in a tamper-proof and verifiable way using cryptographic hashes and digital signatures. Cryptographic hashes are mathematical functions that produce a unique identifier and a proof of content for transactions and data. Digital signatures are mathematical schemes that produce a proof of origin and validity for transactions and data. Blockchain can also protect their integrity and confidentiality using encryption and decryption. Encryption is a technique that transforms data or information into an unreadable form using a secret key or algorithm. Decryption is the inverse technique that transforms data or information back into a readable form using the same or a different secret key or algorithm.