128 vs 256 Bit Encryption

128 vs 256 Bit Encryption: Which one should you use?

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PUREVPNSecurity128 vs 256 Bit Encryption: Which one should you use?

Ever wonder how we maintain the security of our internet data? All of this is made possible by encryption, the unsung hero of digital security. Encryption works like a secret code to prevent our messages, passwords, and other critical information from getting into the wrong hands.

Let’s explore the exciting subject of encryption strength right away. Today, we’ll look at two strong techniques for encryption: 128-bit and 256-bit. If some of these terms seem a little complicated, don’t worry; we’ll explain them in an interesting and fun way.

Prepare to learn which encryption powerhouse is the best option for protecting your digital secrets.

128 vs 256 Bit Encryption

What is Encryption, and why is it useful?

Imagine a secret code that turns your plain, readable data into an unreadable puzzle. That’s encryption for you! It’s an important part of security protocol that protects your sensitive information from prying eyes.

How does it work?

Encryption works wonders by using special algorithms and a secret key to transform your data into ciphertext, a scrambled mess that only the right key can open. It’s like a top-secret language that keeps your information locked away from unauthorized access.

Benefits of using Encryption

Encryption has many benefits:


Encryption ensures that only those with the key can unlock and understand the encrypted information. Even if someone manages to get their hands on your encrypted data, they’ll just see a jumble of characters without understanding anything.

Data Security

Encryption acts like an invisible shield, guarding your data from unauthorized changes or tampering. If anyone tries to mess with your encrypted data, it becomes useless gibberish when decrypted.


It protects your personal and sensitive information, like financial details, medical records, or secret recipes.

Secure Communication

Encryption keeps your data safe from sneaky eavesdroppers when browsing the web or sending messages. It’s like a digital bodyguard, ensuring your conversations stay private and secure.

Many industries have strict rules and regulations that require encryption to keep customer data safe. It helps businesses comply with privacy laws and earn the trust of their customers.

Authentication and trust

It lets you know that the data you receive is genuine and hasn’t been tampered with. Digital signatures, powered by encryption, ensure the sender is verified and the message is intact.

What is AES encryption?

AES, short for Advanced Encryption Standard, is a popular way to protect information. It works by taking chunks of data and scrambling them using a secret key.

128 vs 256 Bit Encryption

Source: Panda Security

AES operates on fixed-size data blocks, like breaking your message into small pieces. Then, it performs its magic and transforms each piece into a secret code that’s hard to crack. This secret code can only be unlocked using the same key used to scramble it in the first place.

In 2000, the U.S. The National Institute of Standards and Technology (NIST) chose AES to replace an older encryption method called DES. AES became the new superhero of encryption, trusted to keep our data safe.

AES is a symmetric encryption algorithm. It means that the same key is used for locking up (encryption) and unlocking (decryption) the data. It’s like having a unique key that fits the lock perfectly.

AES comes in different sizes, small, medium, and large. The sizes are measured in bits, which tell us how strong the encryption is. We’re going to focus on two sizes: 128-bits and 256-bits. The bigger the size, the more secure the encryption.

So, AES encryption is like a secret code that keeps your information safe. It uses a special key to scramble the data and protect it from prying eyes. It’s trusted by experts and has become a standard way to secure our digital secrets.

128-Bit Encryption explained

128-bit encryption refers to the key length used in an encryption algorithm. In the case of 128-bit encryption, the encryption algorithm uses a 128-bit key. 

This indicates that the encryption key comprises a series of 128 binary digits (0s and 1s). A 128-bit key has 2128 combinations, which is a huge number of potential possibilities—roughly 3.4 x 1038. 

With 128-bit encryption, the same key is used to independently encrypt each block of data (usually 128 bits or 16 bytes). Multiple substitution, permutation, and mixing procedures are used during the encryption process.

256-Bit Encryption explained

256-bit encryption refers to the key length used in an encryption algorithm, where the encryption key consists of 256 binary digits (0s and 1s).

With 256-bit encryption, the number of possible key combinations is 2256, which is a vast number, approximately 1.1 x 1077

Like 128-bit encryption, 256-bit encryption involves the encryption of data in fixed-size blocks, typically 128 bits or 16 bytes, using the same key. The encryption process employs multiple substitution, permutation, and mixing operations.

Difference between 128 and 256-Bit Encryption

The main difference between 128-bit and 256-bit encryption is the key length and space. 

Key length

128-bit encryption uses a key length of 128 binary digits (bits), while 256-bit encryption employs 256 bits. 


The critical space for 128-bit encryption is approximately 2128 (about 3.4 x 1038), while the key space for 256-bit encryption is approximately 2256 (around 1.1 x 1077).

Which one is better?


In terms of efficiency, 128-bit encryption generally performs faster compared to 256-bit encryption. The larger key size in 256-bit encryption requires more computational resources and processing power, resulting in slightly slower encryption and decryption operations. 

However, with modern computing capabilities, the performance impact of using 256-bit encryption is usually negligible for most applications, and the difference in efficiency between the two key lengths may be insignificant in practice.

Security against different attacks

Both 128-bit and 256-bit encryption provide strong security against various attacks. However, due to its larger key size and key space, 256-bit encryption offers higher security.

Brute Force Attack

  • A brute force attack is a cryptographic attack method that involves systematically trying all possible combinations of keys or passwords until the correct one is found. 
  • Both 128-bit and 256-bit encryption are resistant to brute force attacks. 
  • However, the larger key size of 256 bits significantly increases the time and computational resources required to exhaustively search the key space.
128 vs 256 Bit Encryption

Source: Townsend Security

Quantum computing

  • Quantum computing has the potential to break traditional encryption algorithms by leveraging the computational power of quantum computers. It has a big impact on asymmetric algorithms, breaking them completely.
  • However, for symmetric algorithms like AES, quantum computing weakens them but doesn’t break them entirely.
  • There is a specific algorithm called Grover’s algorithm, which is used to attack symmetric encryption algorithms like AES. 
  • Grover’s algorithm reduces the effective key length of the encryption algorithm by half. 
  • So, if we consider AES-128, which normally has a key space of 2128 (a very large number), Grover’s algorithm reduces it to 264. For AES-256, the reduction is from 2256 to 2128.
  • While this reduction seems significant, these algorithms still need to be fixed. Even with a powerful quantum computer, it would take an incredibly long time to crack them. 
  • For example, cracking AES-128 with a quantum computer would take about 2.61×1012 years, which is more than 200 times longer than the current age of the universe. Similarly, cracking AES-256 would take about 2.29×1032 years, an even more astronomically long time.

Biclique Attack

  • Biclique attacks are cryptanalytic attacks that attempt to find a collision between two different inputs in the encryption algorithm.
  • Both 128-bit and 256-bit encryption algorithms, such as AES, have undergone extensive analysis and testing to ensure resistance against known attacks, including biclique attacks. 
  • While no practical biclique attack has been found against AES with either key size, the larger key size of 256 bits provides an additional security margin against potential future advancements in attacks.

Where do you need strong encryption?

Strong encryption is needed in various scenarios where data security and confidentiality are crucial. Here are some common areas where strong encryption is necessary:

Secure Communications

Encryption is essential for securing communications over networks. It is used in protocols such as HTTPS for secure browsing, email communication (PGP/GPG), virtual private networks (VPNs), and secure messaging apps. Strong encryption ensures that sensitive information transmitted over the network remains confidential and protected from eavesdropping or unauthorized access.

Data Storage

Encryption protects data stored on devices, servers, or in the cloud. It safeguards sensitive information, such as personal records, financial data, trade secrets, and intellectual property. Encryption ensures that the data remains unintelligible and unusable even if the storage medium is compromised or accessed without authorization.

Financial Transactions

Strong encryption plays a crucial role in securing online financial transactions. It ensures that sensitive information, such as credit card details or bank account numbers, remains encrypted during transmission, preventing unauthorized interception or tampering. Encryption is fundamental to secure online banking, e-commerce platforms, and mobile payment systems.

Healthcare and Medical Records

The healthcare sector handles highly sensitive patient information, including medical records, diagnoses, and treatment plans. Strong encryption is necessary to protect this information from unauthorized access, ensuring patient privacy and confidentiality. It helps meet legal requirements, such as HIPAA (Health Insurance Portability and Accountability Act) in the United States, which mandate the protection of patient data.

Government and Military

Governments and military organizations require robust encryption to safeguard classified and sensitive information. Strong encryption ensures the confidentiality of intelligence data, diplomatic communications, military strategies, and other classified information. It protects against espionage, unauthorized access, and data breaches, thereby maintaining national security.

Personal Privacy

Strong encryption is vital for protecting personal privacy. It allows individuals to secure their data on smartphones, laptops, and other devices, preventing unauthorized access in case of theft or loss. Encryption also helps protect privacy in cloud storage, social media communications, and other personal online activities.

Boost your Security and Privacy with PureMax

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PureKeep: Passwords are the primary defense against cyber attacks and you can keep your first line of defense extra strong with PureKeep, a password creator and manager.

PureEncrypt: If we are talking about encryption, we must remember PureEncrypt. This tool provides bank-grade encryption to safely store all your digital files away from hackers’ reach.


The choice between 128-bit and 256-bit encryption depends on the application or system-specific security requirements and risk tolerance. Both key lengths offer strong protection and are widely used in various industries to safeguard sensitive information.

128-bit encryption is considered secure and has been widely adopted for many years. Still, with quantum computing on the rise, 256-bit encryption offers an extra layer of security due to its larger key size and key space. So, choose the encryption wisely and enjoy safe browsing!

Frequently Asked Questions

What is symmetric and asymmetric encryption?

The same key is used for encryption and decryption in symmetric encryption. AES (Advanced Encryption Standard) is an example of symmetric encryption.
A pair of keys is used for asymmetric encryption, commonly called public-key encryption: a public key for encryption and a private key for decryption. RSA and ECC (Elliptic Curve Cryptography) are two examples.

What is the difference between encryption and hashing?

Hashing and encryption are two distinct cryptographic operations. Hashing is one-way and used for data integrity and password storage, whereas encryption is reversible and used to safeguard data confidentiality.

Is encryption unbreakable?

Although it offers a high level of protection, encryption is not thought to be impenetrable. Key length, the encryption algorithm’s power, and the implementation’s effectiveness all affect how secure an encryption method is. Over time, encryption may become more vulnerable to cryptographic assaults and advances in computing technology.

Can encrypted data be decrypted?

Encrypted data can be decrypted using the correct decryption key. Without the key, it is computationally infeasible to decrypt the data.

Is encryption subject to any legal restrictions?

In different countries, encryption is lawful or illegal. Strong encryption is regulated in some nations and less restricted in others.

Which common encryption algorithms are there?

AES (Advanced Encryption Standard), RSA, ECC (Elliptic Curve Cryptography), Blowfish, Triple DES, and ChaCha20 are widely used encryption algorithms.

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