Overview of Blockchain Technology
Blockchain technology is a decentralized digital ledger system that enables secure and transparent record-keeping across a network of computers, known as nodes. Each transaction is grouped into blocks, which are cryptographically linked to form a chain, ensuring the integrity and immutability of the data. This architecture facilitates trust among parties who may not have pre-existing relationships, allowing for verification and validation of transactions without the need for intermediaries

Types of Blockchains
Blockchains can be classified into three main types based on their access control models:

Private Blockchains
Private blockchains are restricted networks where access is limited to a select group of known participants. These networks are typically governed by a central authority or consortium, which controls membership and transaction validation. Due to their centralized nature, private blockchains often offer enhanced speed and efficiency but come with a theoretical risk of manipulation by the governing entity
 

Public Blockchains
Public blockchains allow anyone to join and participate in the network. These permissionless systems are characterized by transparency and decentralization, as every participant maintains a copy of the ledger. This openness makes public blockchains more resilient to certain types of cyberattacks, as there is no single point of failure
 

Consortium Blockchains
Consortium blockchains are semi-decentralized networks where only a pre-approved group of participants can validate transactions. This hybrid approach seeks to combine the benefits of both public and private blockchains, offering a balance between control and transparency

Security Featuress
The inherent security features of blockchain technology stem from its design principles, including decentralization, immutability, and consensus mechanisms. Cryptographic techniques ensure that tampering with transaction records is virtually impossible, while consensus algorithms, such as proof-of-work and proof-of-stake, validate the authenticity of transactions before they are added to the ledger. Despite these robust security measures, blockchain systems are not immune to cyberattacks; vulnerabilities in the underlying software can be exploited by malicious actors. As blockchain technology continues to evolve, its potential applications expand beyond cryptocurrencies into diverse fields such as supply chain management, healthcare, and voting systems, driving the need for improved security frameworks to protect against emerging threats.