What Does Immutable Mean?

In the cryptocurrency world, it is common to hear the term immutable. But what does immutable mean? And how does it apply to crypto?

Read on to discover everything you need to know about immutable and how it applies in cryptocurrency, blockchain, and beyond!

What Does Immutable Mean?

"Immutable" refers to something that cannot be changed or altered once created or defined. In the context of programming and data structures, immutability means that an object's state cannot be modified after creation.

For example, in many programming languages, strings are often immutable. This means that once you create a string, you cannot change the characters within that string. If you want to change a string, you create a new string with the desired modifications rather than modifying the original string.

Immutability has several benefits in programming, including:

1. Predictability: Immutable objects have a fixed state, which makes it easier to reason about their behavior in a program.

2. Thread Safety: Immutable objects are inherently thread-safe because they cannot be modified, reducing the need for complex synchronization mechanisms in multi-threaded programs.

3. Caching: Immutable objects can be safely cached, as their values never change, leading to potential performance optimizations.

4. Functional Programming: Immutability is a fundamental concept in functional programming, where functions and data are treated as immutable entities, leading to more predictable and maintainable code.

Because cryptocurrency and blockchain are basically software programs created on code, many are automatically immutable.

Related: Centralized vs. Decentralized Gambling

Why is Immutability Important?

Immutability is important for several reasons in various fields, including software development, data management, and even in broader contexts like mathematics and philosophy. Here are some of the key reasons why immutability is important:

Predictability

Immutable objects have a fixed state that cannot be changed. This predictability simplifies understanding and reasoning about code or data, making it easier to debug, maintain, and extend software systems. Developers can be confident that an object's value won't change unexpectedly.

Concurrency and Thread Safety

In multi-threaded or concurrent programming, immutability eliminates the need for complex synchronization mechanisms like locks. Since immutable objects cannot be modified, they can be safely shared among threads without the risk of data races or inconsistent states.

Functional Programming

Immutability is a core principle in functional programming. Functions in functional programming should not have side effects, meaning they don't modify state. Immutable data structures align well with this paradigm and make it easier to reason about and compose functions.

Efficiency

While immutability can create new objects when changes are needed, modern programming languages and libraries often provide efficient ways to create modified copies of immutable objects. In some cases, this can even lead to performance improvements, especially in scenarios involving caching and sharing.

Debugging and Testing

Immutable data structures simplify debugging and testing. Since you can't accidentally modify their state, you can be more confident in the correctness of your code, and testing becomes more straightforward.

Historical Data and Auditing

In systems that need to track historical data or maintain an audit trail, immutability ensures that once a record is created, it cannot be altered. This is crucial for compliance and data integrity.

Security

Immutable data can enhance security by preventing unauthorized changes. For example, in cryptocurrencies like Bitcoin, the immutability of the blockchain ensures the integrity of transactions and ownership records.

Parallelism and Distributed Systems

In distributed systems, where data may be replicated across multiple nodes, immutability helps maintain consistency. Immutable messages or data structures can be safely transmitted and processed across distributed components.

Philosophical and Mathematical Foundations

Immutability has philosophical and mathematical underpinnings in fields like logic and set theory. It plays a fundamental role in the development of rigorous formal systems.

Are There Blockchains That Are Not Immutable?

When you hear the word blockchain, this word is actually somewhat synonymous with immutable. This is because the blockchains were specifically designed to be immutable and, therefore, tamper-resistant. However, what works in theory rarely works in real life, and many blockchains are less immutable than they should be.

In blockchain and crypto, immutability is directly tied to the governance model and design of the specific blockchain. Bitcoin and Ethereum are highly immutable because of their decentralized design and the method by which the network must reach a consensus to execute transactions. Bitcoin and Ethereum are what are known as public, decentralized blockchains.

Private or consortium blockchains don’t always have the same degree of immutability, and this is because a central authority has control over the code of the blockchain and has the power to change the code as needed.

Some of the more popular consortium blockchains are R3 Corda, Hyperledger Fabric, and Quorum.

Related: The Ethereum 2.0 Protocol Basics Explained

What Role Do Forks Play in Immutability?

Although public blockchains like Bitcoin and Ethereum are extremely immutable, the forks that come off these blockchains aren’t always.

A hard fork involves a significant change to the protocol and can result in a split into two separate blockchains (e.g., Ethereum and Ethereum Classic). The new hard fork may be sponsored by a company or central authority, which may lower the immutability of the blockchain.

If you are invested in a blockchain that experiences a hard fork, it is critical to look at the resulting blockchain to understand whether it is still something you want to be invested in.

A soft fork is a backward-compatible upgrade. While these forks can introduce changes, they are usually the result of broad consensus among participants. The original blockchain's history (transactions up to the fork point) remains immutable, but the new chain may have different rules and characteristics.

This means an immutable blockchain, which experiences a soft fork, will retain the original immutability.

Related: A Fork in the Road: Bitcoin vs. Bitcoin Cash

Should You Only Invest in Immutable Blockchains?

At the end of the day, how important immutability is to you will vary from person to person. While it is recommended to invest in immutable blockchains, some people with less risk tolerance may feel safer investing in a blockchain project that isn’t immutable (as long as they trust the central authority behind it!)

Overall, the final decision on whether you invest in an immutable blockchain is up to you. Just remember that investing in cryptocurrency is inherently risky, and you should never invest any money you don’t intend to lose.