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# Encryption Algorithm

## Key Takeaways

• Modern communication and transactions depend on encryption to safeguard data, including messages and medical records, from unauthorized access in a digital environment.
• An encryption algorithm, like those used in public-key and symmetric-key systems, transform plain text into unreadable code, with decryption reversing this process to recover the original data.
• Notable encryption methods include ECC for efficiency, AES (advanced encryption standard) for secure symmetric-key encryption, RSA for public-key security, Blowfish and Twofish for flexible encryption, and Triple DES as an improved DES variant.
• With emerging quantum computing, NIST is developing quantum-resistant encryption standards to ensure data protection remains effective against future technological threats.

An encryption algorithm is a mathematical procedure for performing encryption on data. To put it this in context: encryption algorithms are the backbone of digital security, protecting your  data online, in health institutions and on the blockchain. Yet most people are not familiar with how this technology works.

The discipline of cryptography has a long history, with ancient encryption forms used primarily in military communications. Modern computing has witnessed the emergence and widespread adoption of new encryption methods relying on complex algorithms. Today’s encryption schemes rely on public-key and symmetric-key concepts. The strength of contemporary encryption lies in the difficulty computers face when attempting to crack these codes.

Let’s explore 6 encryption algorithms that secure your data from hackers and unauthorized persons.

## What’s an Encryption Algorithm?

Encryption algorithms are mathematical formulas that convert ordinary text into a confidential code. They make information meaningless by generating seemingly random text. Without the proper deciphering tools, hackers may not access the secured data. Think of encryption as locking sensitive data in a digital safe. Blowfish, AES RC4, RC5, and RC6 are examples of encryption algorithms.

## How Encryption Works

An encryption algorithm takes your original information written in plain text and changes it into a random string of characters known as a ciphertext. Only the correct decryption key can decipher the secret text and recover the initial data. This back-and-forth process ensures that your information remains confidential and secure.

### Decryption

Decryption is the reverse process of deciphering your encrypted data. It transforms the ciphertext back into its original, readable form. To do this, you need a decryption key, which acts like the key to your digital safe.

### Key

A key is a unique code that encrypts, decrypts, or encrypts and decrypts data. It determines whether your data remains safe or becomes exposed. The length and complexity of a key directly impact the security of your encrypted information. Longer, more complex keys are more difficult to crack.

Symmetric and asymmetric encryption systems take different approaches to keys. Symmetric encryption methods use the same key to encrypt and decrypt data, while asymmetric systems use a public key to encrypt data and a private key to decrypt it.

## Common Encryption Algorithm Examples

Let’s explore the most widely used methods to secure data.

### 1. Elliptic Curve Cryptography

Elliptic Curve Cryptography (ECC) is a public key encryption algorithm that can be used for encryption, authentication and digital signatures. ECC generates keys using elliptic curve  equation, which results in smaller keys than RSA.

ECC offers several advantages. Smaller keys mean less data to handle, which is great for devices with limited memory or slow connections. Additionally, ECC is faster than traditional methods, saving battery life on mobile devices. Despite its smaller keys, ECC provides robust security thanks to the unique properties of elliptic curves.

While ECC presents compelling benefits, it’s essential to acknowledge its challenges. Patents on some ECC algorithms initially impeded their widespread adoption. Furthermore, implementing ECC properly requires expertise to avoid vulnerabilities. Despite these hurdles, the increasing number of patent-free options and growing awareness of ECC’s strengths are driving its wider acceptance.

Elliptic curve cryptography is what underpins blockchain technology, as well as being the cornerstone of online banking and email security.

### 2. AES

AES, Advanced Encryption Standard, is a highly secure encryption technique, with the AES 256-bit iteration known to be the most secure encryption method commercially available today.

Developed by the National Institute of Standards and Technology (NIST) in 2001, AES has become a global standard for secure communication.

AES employs symmetric encryption, meaning it uses a single encryption key for both encoding and decrypting data. This approach differs from asymmetric encryption, which requires two separate keys. AES offers three key lengths: 128, 192, and 256 bits, with longer keys providing better encryption.

AES’ development was to overcome the limitations of its predecessor, DES (Data Encryption Standard). As computing power advanced, DES’s 56-bit key became vulnerable to brute-force attacks. To address this, NIST initiated a public competition to find a replacement that would offer superior security while maintaining efficiency.

The AES method is now widely used in digital security, including WiFi, VPNs and clous storage services.

### 3. RSA Security

RSA (Rivest-Shamir-Adleman) is an encryption algorithm used to secure data transmission. It was developed by RSA Data Security, Inc, named after the RSA algorithm co-creators.

Instead of a single key like AES, RSA uses a pair: a public key and a private key.

The public key is shared openly, while the private key remains a secret. Data encrypted with the public key can only be decrypted with the corresponding private key, ensuring secure communication.

RSA was developed in the 1970s to address the growing need for secure digital communication. Its foundation lies in the mathematical challenge of factoring large numbers, making it incredibly difficult for hackers to break the encryption.

Today, RSA is ubiquitous. It’s the foundation for secure connections for online banking, email, and countless other digital services. However, while RSA is robust, it’s not invincible. Factors like security key length determine its effectiveness.

### 4. Blowfish

Blowfish is a type of symmetric encryption that uses a block cipher. It was developed by Bruce Schneier and debuted to the cryptographic community in 1993.

Designed as a swift, secure, and versatile alternative to existing encryption methods, Blowfish challenged the norm with its openness. Unlike its predecessors, Schneier generously shared the Blowfish algorithm, allowing more people to use Blowfish across various applications and systems.

Developed as a response to the limitations of older encryption standards, Blowfish offered a faster and more robust solution. Its flexibility, allowing for various key lengths, added to its appeal.

Today, while newer encryption methods have taken center stage, Blowfish’s impact on cryptography remains undeniable. Its lasting impact highlights the ongoing effort to ensure secure digital communication.

### 5. Twofish

Twofish is a symmetric key block cipher that emerged as a strong encryption standard contender in the late 1990s. Created by Bruce Schneier and his team, it aimed to replace the aging Data Encryption Standard (DES). Unlike DES, Twofish operates on 128-bit blocks and supports flexible key sizes of 128, 192, or 256 bits, adapting to various security needs.

The weaknesses discovered in DES encryption prompted the development of Twofish. Its creators sought an algorithm immune to cryptanalysis and efficient across different platforms. While not chosen as the Advanced Encryption Standard (AES), Twofish remains a respected option because of its robust security features.

Twofish boasts several advantages. It has withstood rigorous cryptanalysis, demonstrating its security. The algorithm’s flexibility in key sizes meets diverse security requirements. Additionally, Twofish performs efficiently on software and hardware, making it versatile for different applications.

While secure, Twofish is not immune to vulnerabilities. Side-channel attacks, such as timing and power analysis, pose potential threats. Twofish’s computational intensity might also limit its suitability for low-power devices or resource-constrained environments.

Despite not being the AES, Twofish finds applications in software prioritizing security, like disk encryption tools. Its reputation for security and efficiency ensures its continued use in various systems demanding high data protection.

### 6. Triple DES

Triple DES, or 3DES for short, is an encryption method designed to enhance Data Encryption Standard (DES) security. Improved computing power made DES, once the industry standard, susceptible to attacks. Triple DES encryption employs the DES algorithm three times for every data block to counteract DES vulnerabilities.

Triple DES encryption operates on a block cipher principle. It encrypts data in fixed-size blocks. The process involves three distinct steps:

• Key Expansion: This generates 3 keys, each 56 bits long. These keys are crucial for the encryption and decryption processes.
• Encryption: Divides data into 64-bit blocks. Each block undergoes three rounds of encryption: first using Key 1, then decrypting with Key 2, and finally encrypting again with Key 3. This layered approach enhances security.
• Decryption: Reverses the process to recover the data: decryption with Key 3, encryption with Key 2, and decryption with Key 1.

This layered approach involves using three different keys, making it harder for attackers to crack the code. Triple DES improved upon its predecessor, but modern encryption standards like AES outpace. Nevertheless, it remains a valuable tool in specific applications, especially for systems that require compatibility with older DES-based infrastructure.

## Symmetric Key Systems

Symmetric key systems employ a single, shared encryption key for encoding and decrypting data. Think of it as two people using the same key to lock and unlock a box.

This approach prioritizes speed and efficiency, making it suitable for handling large volumes of data. AES, a widely adopted standard, exemplifies this system’s strength. Other notable algorithms include DES, 3DES, Blowfish, and Twofish.

### Advantages of Symmetric Key Algorithms

Symmetric key algorithms offer several advantages. First, they’re fast, which makes them ideal for handling large data volumes. Second, their simplicity shines through—the concept is relatively easy to grasp and implement. Lastly, they are efficient, demanding fewer computational resources than their asymmetric counterparts.

### Risks of Symmetric Key Systems

While efficient, symmetric key systems come with inherent risks. Securely distributing the secret key between parties presents a significant challenge. Managing and protecting multiple keys can be complex. Perhaps most critically, if the key falls into the wrong hands, it exposes the system’s security. As the number of communicating parties grows, key management becomes exponentially more difficult.

Find out more about symmetric key systems in our detailed explainer.

## Asymmetric Key Systems

Asymmetric key systems, also called public-key cryptography, have two linked keys— a public key and a private key. The public key can be freely shared, but the private key keeps everything secure. It’s the only key to deciphering the data and is crucial for countless digital interactions.

### Advantages of Asymmetric Key Algorithms

Asymmetric key systems offer several benefits.

• Asymmetric encryption is secure because the private key is never distributed.
• They simplify key management by removing the secure distribution of a shared key.
• Users can sign messages with private keys to authenticate and verify the sender’s identity.
• The decryption key – or public key – can be shared publicly without any risk to the concealed data.

### Risks of Asymmetric Key Systems

While incredibly useful, asymmetric key systems have their challenges. They include:

• Asymmetric encryption slows down data processing compared to symmetric encryption.
• Asymmetric encryption requires larger key sizes, potentially impacting performance and storage.
• Security vulnerabilities can result from implementation flaws or algorithm weaknesses, risking data confidentiality.
• If the private key is ever compromised, the underlying data is no longer secure.

## Encryption Use Cases

Encryption safeguards sensitive information. It finds applications across various industries.

### Online Banking

Encryption protects your financial data during online transactions, from outsiders when you log in, transfer funds, or pay bills, secures your account, and blocks unauthorized access.

### Healthcare Data Protection

Healthcare relies on encryption to protect patient privacy. Medical records, including sensitive personal and health information, are encrypted when stored and transmitted. This compliance with regulations ensures that only authorized medical professionals access patient data.

### Cloud Storage Security

Cloud providers employ encryption to protect data stored on their servers. Even if a cloud account is compromised, the encrypted data remains inaccessible to unauthorized individuals.

### End-to-End Encrypted Messaging

Messaging apps like WhatsApp and Signal use end-to-end encryption to protect your conversations. Only you and the recipient can read your messages, as they are encrypted on your device and decrypted on theirs. Not even the messaging service can access the content.

### E-commerce Security

When you make a purchase, your payment information is encrypted to prevent data theft. Your credit card details and personal information remain confidential during transmission.

These examples highlight the critical role of encryption in securing sensitive data across various sectors. By protecting user data, encryption builds trust and safeguards privacy.

### Blockchain Technology

Encryption ensures secure and verifiable transactions in blockchain networks. ECC is integral to generating and verifying digital signatures. Elliptic curves generate more compact yet potent keys than traditional methods, resulting in the efficiency of ECC.

Bitcoin and Ethereum use ECC to generate key pairs to sign and legitimize transactions. The private key signs transactions transactions, verifying that you have the authority to control a given wallet. It also acts as a decryption key, enabling you to access crypto that has been sent to your wallet, while keeping everyone else out. Meanwhile, the public key acts as an encryption key: it enables anyone to securely send crypto to your blockchain address, and prevents that transaction from being intercepted by a third party.

ECC enhances security while minimizing computational demands, making it ideal for secure, high-performance cryptographic operations essential to blockchain applications.

## NIST and the Future of the Encryption Algorithm

The National Institute of Standards and Technology (NIST) is leading the charge in safeguarding our digital world from the looming threat of quantum computers. These machines might crack today’s encryption algorithms, leaving our sensitive data vulnerable.

NIST has responded proactively by spearheading the development of quantum-resistant encryption algorithms. These may withstand the computational power of quantum computers, ensuring continued protection of our digital assets.

A crucial step came in 2022 when NIST announced the selection of four algorithms to form the foundation of a new post-quantum cryptography standard.

As quantum computing technology advances, NIST’s work in developing and standardizing quantum-resistant encryption remains paramount. Their efforts provide a crucial shield, protecting our data and maintaining trust in the digital realm.

## FAQ

### What is NIST?

NIST (National Institute of Standards and Technology) is a US government agency that develops and promotes cryptography standards. It plays a crucial role in creating secure encryption methods used worldwide, from e-commerce to government communications. NIST also leads research on post-quantum cryptography to protect against future threats.

### What Makes An Encryption Algorithm Symmetric?

A symmetric encryption algorithm uses a single, shared secret key for both encrypting and decrypting data. It’s like using the same key to lock and unlock a door. While efficient, symmetric encryption is vulnerable if the key is compromised. To address this, it’s often combined with asymmetric encryption for key distribution.