Blockchain in depth: Public vs. private blockchains, infrastructure considerations and more

For IT leaders, the important question is not whether blockchain is “the next big thing.” 

The question is actually much simpler: where and how does this technology solve real problems better than conventional architectures?

To answer that, let’s begin with the fundamentals.

What blockchain really is, and how it works

A blockchain is a distributed database made up of blocks of data linked together in chronological order. Each new block contains information about transactions or events, along with a cryptographic reference to the previous block. This creates an auditable chain of records that is extremely difficult to alter retrospectively.

Unlike a traditional database, which is generally administered by one organisation, a blockchain is maintained collectively by participants in the network. Copies of the ledger are distributed across multiple systems, helping to ensure synchronisation, resilience and transparency.

When a transaction is submitted to a blockchain network, it is checked according to the rules of that network. Once validated, it is added to a block and propagated across the network so that participants agree on the updated state of the ledger. This agreement process is known as consensus.

The result is a system designed to support tamper-resistant, highly available and traceable record-keeping.

Public, private, permissioned and permissionless blockchains

Not all blockchains work in the same way. For business leaders, one of the most important distinctions is the difference between public and private networks, and between permissioned and permissionless models.

Public blockchains are open networks. In general, anyone can access them, and they are often designed for broad transparency and participation. These networks are especially relevant where openness, interoperability and shared trust are important.

Private blockchains are restricted to a specific organisation or group of participants. They are usually designed for tightly controlled business processes, where governance, confidentiality or performance requirements call for more control.

A second distinction concerns permissions.

In a permissionless blockchain, participants can typically join the network and interact with it without prior approval, provided they follow the network’s technical rules.

In a permissioned blockchain, roles and actions are controlled more tightly. Specific participants may be allowed to read, write, validate or administer the network based on predefined permissions.

These models are not interchangeable. The right choice depends on the use case, the governance model, the sensitivity of the data, and the degree of openness required.

How infrastructure factors in

Blockchain discussions often focus on tokens, protocols or applications. But for IT decision-makers, infrastructure is just as important.

A blockchain environment depends on reliable underlying systems to ensure performance and trust. Three requirements stand out in particular: security, speed and uptime.

1. Security

Security is indispensably foundational. Blockchain networks are designed to preserve data integrity, but they still need to be protected at the infrastructure and operational levels.

This includes safeguarding validator or node environments, protecting sensitive data during processing, enforcing strict identity and access controls, and defending services against network attacks such as DDoS events. In some blockchain contexts, security solutions must also be tailored carefully so that legitimate high-volume traffic is not mistaken for malicious traffic.

2. Speed and low latency

Many blockchain applications are highly sensitive to latency. Validation, data propagation and user-facing responsiveness all depend on fast, stable connectivity.

This is especially relevant for environments such as decentralised finance, exchanges, validator operations, RPC services and analytics pipelines, where milliseconds can affect performance and user experience. The network layer matters a great deal: bandwidth, routing quality, geographic distribution and private interconnection can all influence outcomes.

3. High availability and resilience

Blockchain systems are expected to operate continuously. Downtime can mean missed transactions, degraded service, failed validations or loss of trust.

That makes blockchain’s resiliency critical. Distributed hosting, strong service-level commitments, redundancy, and multi-regional design can all play an important role in keeping blockchain workloads available and synchronised.

For IT leaders evaluating providers or architectures, blockchain should therefore be treated as both an application question and an infrastructure question.

Blockchain goes beyond cryptocurrency

Perhaps the biggest misconception for blockchain is that it begins, and ends, with crypto.

Cryptocurrency is just one application of blockchain, and it is far from the only one. The technology can also support a wide range of business and public-sector use cases where transparency, traceability, automation or shared trust are needed.

Examples include:

• Digital identity and access models, where blockchain can help verify claims or credentials while preserving control and traceability
• Supply chain tracking, where organisations need reliable visibility into provenance, handling and transfers across multiple parties
• Smart contracts, which can automate actions when predefined conditions are met
• Decentralised applications, where services run on distributed infrastructure rather than a single central backend
• Enterprise recordkeeping, where multiple stakeholders need a shared, verifiable source of truth

The key point is that blockchain is valuable beyond the fact that it is decentralised. It is valuable when decentralisation, immutability and shared verification solve a real business or operational challenge together.

A practical view for IT leaders

For IT leaders, blockchain should be approached with the same discipline as any other architecture decision.

And that means asking:

• What trust problem are we solving?
• Do we need a shared ledger across multiple parties?
• What governance model fits the use case?
• What are the performance, security and compliance requirements?
• Which infrastructure will support this reliably at scale?

In some cases, a conventional database will still be the right answer. In others, blockchain offers a stronger foundation for transparency, resilience and distributed trust.

The important thing is to move beyond the hype. Used in the right context, blockchain is a practical architectural model with applications that extend well beyond cryptocurrency.

As adoption grows, IT leaders who understand both the technology and its infrastructure requirements will be those best placed to identify where it can deliver meaningful business value.

 

This article is based on the guide “The Blockchain Blueprint”, available to download for free.