Structural Difference between Traditional Databases and Blockchain

DLT is a form of a distributed database. Both blockchain and traditional databases store data, but there are fundamental differences in their structures. The traditional database has a central authority (administrator) to maintain, control, replicate/ distribute the data, and distribute read/write privileges to other authorities. Also, traditional databases run over a centralized network. Often, databases run in private networks behind a firewall in data centers, where control, security, and trust are handled by big enterprises that provide storage services. By contrast, blockchain is a digital ledger that receives, encrypts, distributes, and stores transactions, without requiring a trusted third party (i.e., disintermediation). For example, today’s Bitcoin, for cryptocurrency [35]. The blockchain storage method is formed by a linear series of blocks, each connected to the previous one in a sequence that provides high data immutability and transparency. In this section, we highlight features that make block- chain superior, as a base for data.

Immutability of Blockchain

In contrast to centralized databases, stored data in the blockchain is not erasable and is almost impossible to modify. Blockchain is unlike a traditional database, which allows users to perform create, read, update, and delete operations (C.R.U.D); blockchain allows only insert and read operations. Blockchain stores transactions in a block, then links them to each other by a Merkle root algorithm [36], as shown in Figure 6.6. Then, blockchain connects all the blocks by encrypting the blocks’ information, including the previous block’s “hash” to form an interconnected chain.

A Merkle root hash is the ultimate encryption result for the transactions included in a block, to provide the immutability of the transaction. Therefore, any change, no matter how simple, in the transaction w'ithin the block leads not only to changing the Merkle root hash but also to changing the block hash, leading to a break in the chain.

FIGURE 6.6 Merkle root tree, example.

Performance

Traditional databases are very fast compared to the blockchain, because the latter uses cryptography to link its blocks and also employs the consensus principle to provide full distribution, by allowing the majority of peers to agree on the outcome of the transaction, to accept it into the chain. Every node in a blockchain network contains a copy of the full data ledger, so any node experiencing failure will be shut down, not affecting the network that completes its work over the other nodes. In the case of distributed databases, the trust factor between the parties must be significantly guaranteed to preserve data integrity. Blockchain operationally repeals the trust factor, to allow an independent transfer of transactions regardless of the identity of the parties. In conclusion, traditional databases are fast but not fully distributed. Permissionless blockchains use the principle of consensus, which makes them slow; however, permissioned blockchains are relatively fast, while not exactly fully distributed.

Robustness and Disintermediation

Blockchain transactions contain their proof of validity and their proof of authorization, instead of requiring some centralized application logic to enforce those constraints. Transactions can, therefore, be verified and processed independently by multiple “nodes,” with the blockchain acting as a consensus mechanism to ensure those nodes stay in sync. This mechanism is the essence of the blockchain, which enables the sharing of ledgers across boundaries of trust, without requiring a central dominator node.

Blockchain Technology as the Future of Cybersecurity

Nowadays, current technological developments facilitate the generating and accessing of data everywhere. This creates difficulties as people try to maintain their privacy, especially their personal and sensitive data stored and transmitted over internet networks by smart phones and computers. Data is the most valuable asset in today’s world (the information era), and it is the tool that helps the world’s largest known companies to grow' bigger, from Wikipedia, Facebook, and Amazon to other social networking sites. Thus, protection methods should have evolved, to combat the currently developed methods of intrusion, penetration, and destruction.

Before the emergence of distributed ledger technology, organizations used to privilege a limited number of trusted employees to access sensitive data. However, trustworthiness is insufficient as a factor to preserve data security. There are many questions about the concept of trust in this area, such as whether an employee is reliable. The answer will always be vague and is likely to change over time. Trusting an unworthy intermediary leads to the loss or theft of sensitive data or intrusions into it. In the last decade, the blooming of blockchain and its first implementation (Bitcoin) have encouraged the world to consider the possibility of dispensing with the trusted party, w'hether an organization or a person. Blockchain provides the following key benefits to improve cybersecurity, due to its intrinsic design features:

FIGURE 6.7 (a) Blockchain network structure, (b) Traditional database network structure.

• 1. Distribution Aspect to Secure Data: Blockchain distributes data across the entire network, to be stored in every node in a replicable manner, instead of using a single repository of data or cloud storage. Figure 6.7 shows the differences between the structures of a blockchain network and a traditional database network. Hence, data loss is almost reduced to zero, because, as mentioned earlier, if one or more nodes go down, the data is not affected, unless the entire network of all nodes fails, which has an extremely low' probability. Cutting out the middle man, the central authority, or the trusted third party in processing data achieves a distributed immutable ledger of data records.
• 2. Encryption and Validation: Blockchain is built on two foundations, the distribution and serialization of blocks, a mechanism that provides data credibility and integrity (irrevocable data). Let us take a scenario of file integrity verification, by generating a digital signature for a particular file and then storing it in a blockchain. The integrity of the file can be confirmed by matching the stored signature w'ith the validated file signature, to verify that no alteration has affected the file as long as the blockchain network has been running. On this basis, the encryption and verification of the blockchain help to increase the protection of data from unwarranted reading, manipulation, and forgery.
• 3. Difficulties in Hacking: Traditional database networks are often vulnerable to malicious attacks that allow tampering and cause data corruption. A blockchain network can counter hacking attempts, as proven in its first application, Bitcoin. This technology encrypts data, appending it to blocks and then connecting those blocks, after which data is distributed across the peer-to-peer network, to obtain sufficient data privacy. Therefore, attackers must break the majority of the network nodes at once, w'hich is practically impossible, because it would require infeasible computing power and time.
• 4. Blockchain Diversity: The blockchain “fever” that began in the last decade led to the creation of various versions, such as private, public, and hybrid blockchains. Every type provides beneficial features that can be utilized in various domains. For example, public blockchain provides transparency and full distribution (decentralization), which in turn is very beneficial for many kinds of transactions, for example, involving money, contracts, ownership, and copyrights. Private blockchain also allows the use of a P2P network, but is partially distributed among known parties, which in turn is suitable for banks, transportation companies, and health care companies. Hybrid blockchain would cater to a mixture of both private and public blockchain operations, depending on its design.