Infographic: How encryption has shaped history and will define the future

Privacy newsVideo
6 mins

From ancient Sparta to the age of quantum computing, the art of encryption has woven an intricate thread through history, shaping the way we safeguard our personal data and communications.

In the days of spears and shields, Spartan warriors employed a simple yet ingenious method known as the scytale to encode their messages. Fast forward to today, and we find ourselves in a digitally connected realm protected by VPNs—modern-day sentinels of secure digital communication. A VPN download enables you to encrypt data transmitted to and from your device, scrambling it in a way that can’t be read by anyone other than the intended recipient.

However, on the horizon, a new challenge looms: quantum computing. With unprecedented computational power, quantum machines threaten to disrupt our current encryption methods by making them breakable. The race is on to develop quantum cryptography, a critical defense against this emerging threat.

Join us as we journey through time, where we unravel the history of encryption, and look toward the exciting frontier of quantum-resistant security, that’s set to redefine the way we protect our data.

What is encryption and why do we need it?

Encryption serves as an important safeguard in our digital world. It involves changing data into a code to prevent unauthorized access. Once a practice reserved for military and government use, it’s evolved into a common tool for online security—protecting personal information and upholding privacy rights. 

Encryption forms the backbone of cybersecurity. By converting data into an unreadable format, it thwarts cybercriminals attempting to intercept sensitive information. 

Encryption also ensures the confidentiality of data such as patient records in healthcare, financial transactions in e-commerce, and online banking details. And beyond individual protection, it’s fundamental in safeguarding national interests. Encryption shields classified information and secures critical communications, standing as a cornerstone of security measures throughout history.

Just how secure is encryption? As an example, ExpressVPN uses AES-256, the same encryption standard adopted by the U.S. government and trusted by security experts worldwide to protect classified information. It uses a 256-bit cryptographic key to convert your plain text or data into a cipher. A brute-force attack on a 256-bit keyspace is simply infeasible, even if all the world’s most powerful supercomputers ran for as long as the universe has existed so far, billions and billions of times over.

But that’s modern, digital cryptography. From its early rise in Sparta and Ancient Rome to its pivotal role in both World Wars, we trace cryptography’s timeline right from the very start:

5 biggest threats to encryption

While encryption has long been an effective defense against breaches, communication interception, and data compromises, technological advancements have brought forth a new set of challenges:

1. Quantum computing 

The rise of quantum computing presents a double-edged sword for encryption. On the one hand, it offers the potential for more robust encryption keys that are resistant to even the most powerful supercomputers. On the other, it also threatens the integrity of commonly used encryption methods like RSA, which could be broken by quantum computers in the near future.

2. Key security

Encryption keys are the foundation of modern encryption. If an attacker is able to obtain the encryption key, they will be able to decrypt the data. This is why it’s essential to keep encryption keys secure. However, there are a number of ways that encryption keys can be compromised, including through social engineering attacks, data breaches, and malware infections.

3. Blockchain and monetary security

Blockchain technology is increasingly being used to protect data and transactions. However, blockchain is not without its vulnerabilities. For example, if an attacker is able to control a majority of the nodes on a blockchain network, they could potentially execute a “51% attack” and reverse or modify transactions. Blockchain wallets are also often targeted by hackers, as they can contain large amounts of cryptocurrency.

4. Law enforcement pushback 

Encryption makes it more difficult for law enforcement to investigate crimes. Criminals use end-to-end encrypted chat apps just as we all do, and their communications would understandably be a trove of evidence and leads for solving crimes. This has led to calls for backdoors in encryption, which would allow law enforcement to access encrypted data without the suspect’s knowledge or permission. However, many would argue that technology that uses backdoors by definition is no longer end-to-end encrypted and would be a major loss for privacy advocacy.

5. The human factor

Human error is one of the biggest threats to encryption. For example, employees may accidentally expose encryption keys, or they may be tricked into clicking on malicious links that install malware that can steal encryption keys. 

The future of encryption: Securing our data in the quantum age

The evolution of encryption is a testament to our dedication to safeguarding digital data. However, in a world increasingly reliant on technology, protecting our sensitive information has never been more important. 

In the face of the advanced threats mentioned above, and other formidable challenges, a new era in digital security is emerging. Experts are meeting these hurdles head-on, bolstering our digital lives with innovative solutions. These include: 

Post-quantum cryptography

Quantum computing is set to revolutionize encryption. Unlike traditional methods, which rely on complex math problems, quantum computing presents entirely new challenges. Its immense computing power threatens to quickly solve mathematical puzzles that were previously unsolvable for classical computers. 

Quantum cryptography, a groundbreaking approach, uses the unique properties of quantum particles for secure communications. This paradigm shift ditches classical math algorithms, providing an unbreakable foundation for encoding and decoding information. Both companies and governments are heavily investing in research and development to unlock quantum and post-quantum cryptography’s full potential. 

ExpressVPN leads the way in this field, being among the first VPNs to implement advanced post-quantum protections. Our post-quantum security is built on the foundation of wolfSSL’s integration with the Open Quantum Safe team’s liboqs (an open-source library for quantum-safe cryptographic algorithms). The encryption relies on the National Institute of Standards and Technology (NIST)-approved Kyber algorithm, ensuring robust defense against quantum computing threats. This cutting-edge protection is available to users through the latest version of the ExpressVPN apps for Android, iOS, Linux, Mac, and Windows.

“Post-quantum algorithms are still relatively new and less battle-tested,” explains Peter Membrey, Chief Engineering Officer at ExpressVPN. “By leaving classical cryptography in the hands of existing tried-and-true standards, we can ensure any unforeseen issues with post-quantum algorithms don’t impact the security or integrity of the broader cryptographic infrastructure—and by extension the security of users.”


The blockchain, once synonymous with cryptocurrencies, has matured into a powerful platform with multifaceted applications, including encryption. Its decentralized nature and use of cryptographic functions make it a strong defense against tampering and unauthorized entry.

Smart contracts, a key innovation within the blockchain ecosystem, could provide an automated layer of security. These self-executing contracts directly enforce the terms of an agreement, bypassing the need for intermediaries.  

Homomorphic encryption

Homomorphic encryption is a game-changer in data security. Unlike typical encryption, which needs decryption for computations, it lets you perform operations on encrypted data directly. This breakthrough enables secure computations while keeping the underlying information private.

As industries grapple with the growing demand for secure cloud-based services and data analytics, homomorphic encryption is becoming increasingly important. By allowing computations on encrypted data, it strikes a balance between data privacy and usefulness. It holds the potential to transform fields from healthcare to finance.

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