Encryption Key

Key Takeaways

Since Data encryption is the cornerstone of secure digital interactions, from banking and emails to ecommerce and crypto. Over 80% of the web pages opened by Firefox are using HTTPS, highlighting the importance of encryption in the modern world. No matter what type of encryption you’re using, or what field you’re using it in, encryption keys lie at the heart of your data security.

So in this article, we’ll advance your understanding  of encryption by unpacking the concept of an encryption key. We’ll discuss different types of key, how to use them, how to generate them and what makes these keys different from a password.

What Is an Encryption Key?

An encryption key is a string of characters that an encryption algorithm uses to encodealter data. Once plaintext is encoded via this algorithm, it becomes unreadable to anyone who doesn’t possess the cryptographic key. The encoded data – or ciphertext – can only be decoded back to its original plaintext form with the corresponding key.

Encryption keys can vary in length and complexity and this affects the level of security they provide. The longer and more complex a key is, the harder it is for potential attackers to crack it. However, length isn’t the sole deciding factor. For example, the AES 256-bit encryption key is widely used today. At the same time, according to Microsoft 1024-bit RSA is now vulnerable to cyber attacks due to the advancement of technology.

How Does an Encryption Key Work?

Encryption keys operate in conjunction with an algorithm, scrambling data into an unreadable format. 

The process begins with the original data, also known as plaintext. The encryption algorithm transforms this original data into ciphertext (encrypted data) by using the encryption key. This creates an encoded version of the data that is unreadable. 

To decode the ciphertext back into readable plaintext, the corresponding decryption key is required. This key might be the same one used for encryption (symmetric encryption) or a different, corresponding one used just for decryption (asymmetric encryption).

Asymmetric Encryption vs. Symmetric Encryption

Organizations widely use two main types of encryption to protect information: symmetric and asymmetric encryption. You need to understand these two primary types of encryption to grasp how encryption keys function.

Symmetric Encryption

Symmetric encryption uses only one key for both encryption and decryption. This method is straightforward and efficient, making it suitable for encrypting large amounts of data quickly. However, this is also a double-edged sword: the main challenge in symmetric encryption lies in securely sharing the key between the sender and recipient. If any unauthorized party manages to intercept the key, the entire encryption system will be compromised. 

Some of the most common symmetric encryption algorithms include AES (Advanced Encryption Standard) and DES (Data Encryption Standard).

Asymmetric Encryption

On the other hand, we have asymmetric encryption. It’s also known as public key cryptography and it employs a pair of keys. The pair includes a public key for encryption and a private key for decryption. You can share the public key openly, but the private key must remain hidden. Asymmetric encryption enhances security by eliminating the need to share the decryption key. On the downside, if the private key is ever lost, there is no way to retrieve the information.

Some of the most widely used asymmetric encryption algorithms are RSA (Rivest-Shamir-Adleman) and ECC (Elliptic Curve Cryptography).

Encryption Key Use Cases

Encryption keys are fundamental in various real-world applications:

• Online Banking: Secure online transactions rely on encryption to protect sensitive financial information, preventing unauthorized access and fraud. Encryption ensures that data such as account numbers and passwords are transmitted securely between a user and banking institutions.
• Email Communication: Encryption limits the contents of an email only to the intended recipient. By encrypting emails, users and businesses can protect sensitive information from being intercepted or accessed by unauthorized parties.
• Cryptocurrencies: Public and private keys secure transactions and digital wallets, providing a secure method for transferring and storing digital assets. This cryptographic process guarantees that only the owner of the private key can authorize transactions from their crypto wallet.
• Data Storage: Encrypting files and databases safeguards against unauthorized access. Organizations and individuals use encryption to protect sensitive data stored on devices and in the cloud. Even if the data is accessed or stolen, it remains unreadable without the corresponding key.
• Healthcare: Encryption is used to protect patient records and sensitive health information. This makes medical data only accessible to authorized healthcare providers and patients.
• Government and Military: Encryption is vital for protecting classified and sensitive information from cyber threats and espionage. This makes it a vital tool within the government and military. It allows for secure communication channels and encrypted data storage to help maintain national security.
• Telecommunications: Voice and video calls, as well as messaging services, use encryption to prevent eavesdropping and unauthorized access. Every major social platform uses encryption to secure the privacy of users.
• E-commerce: Online retailers use encryption to secure payment information and personal details of customers during transactions. This prevents data breaches and potential leaks of customer information.

How Are Encryption Keys Created?

Creating secure encryption keys involves two parties agreeing on the same string of data that they will then use to encrypt their communications. As a result, this string of data involves several critical considerations, all of which affect its security:

Length

The length of an encryption key can significantly impact its security. Longer keys are generally more secure because they offer a larger number of possible combinations. This makes it more difficult for attackers to crack the encryption through brute force. For instance, AES can use key lengths of 128, 192, or 256 bits, with 256-bit keys providing the highest level of security.

Entropy or Randomness

Entropy refers to the randomness in generating cryptographic keys. High entropy leads to the creation of keys that are unpredictable and resistant to attacks.  You can derive randomness from physical processes, such as electronic noise or mouse movements, making each key unique and secure.

Encryption Key Management

Effective encryption key management is crucial in maintaining a high level of security. It involves generating, storing, using, and eventually revoking keys securely. This process makes it so that keys remain protected throughout their lifecycle, minimizing the risk of unauthorized access and data breaches.

Key Exchange Explained

Key exchange is the process of securely exchanging encryption keys between parties, where a symmetric encryption algorithm is being used. It is crucial in establishing a secure communication channel.

Diffie Hellman Key Exchange Algorithm Explained

Two parties can use the Diffie-Hellman key exchange algorithm to generate a shared secret key over an insecure channel. Each party generates a public-private key pair and exchanges the public keys. Using their private key and the other party’s public key, they independently compute the shared secret key. This shared key can then encrypt subsequent communications.

Where Is Key Exchange Used?

Key exchange is used in a number of different settings where cryptography is employed. Let’s take a look at a few examples:

HTTPS

HTTPS (Hypertext Transfer Protocol Secure) uses key exchange algorithms during the initial SSL/TLS handshake to establish a secure connection between a web browser and a server. Thanks to this process, the data transmitted over the internet remains confidential and tamper-proof.

Telnet

Telnet is a protocol for remote communication and it employs encryption key exchange to secure data transmitted between a client and a server. By encrypting the communication channel, Telnet prevents eavesdropping and unauthorized access.

SSH

SSH (Secure Shell) is a protocol used for secure remote login and other network services. It relies on key exchange algorithms to establish a secure connection, enabling encrypted data transmission between the client and server.

Encryption Key vs. Password

While an encryption key and a password both safeguard private data and have some similarities, there are also some notable differences.

Similarities

• Entropy: Encryption keys and passwords require high entropy to ensure security. A key or password with more randomness is harder to crack. If the password or key is weak, a hacker can easily guess it via a brute force attack.
• Secrecy: Both must remain confidential to maintain security. If anyone finds out your password or encryption key, the information that they’re protecting is as good as lost.

Distinctions

Despite sharing similar objectives and features, there are nonetheless some major distinctions between passwords and encryption keys. Let’s take a look below:

 

Closing Thoughts

Encryption keys are the cornerstone of modern data security. They ensure that sensitive information remains confidential and secure. By understanding how encryption keys work, users can better protect their data.

While technology continues to evolve, so too will the methods of securing our digital world. Hence why understanding the principles of encryption is so fundamental.

FAQ

What Is Entropy in Encryption?

Entropy in encryption refers to the randomness collected by a system to generate cryptographic keys. High entropy ensures that keys are unique and resistant to attacks, making them more resilient to brute-force attacks.

How Does Asymmetric (Public Key) Encryption Keep Data Secure?

Asymmetric encryption involves using a pair of keys, a public key for encryption and a private key for decryption. These keys serve different functions, so you must treat them differently.

Since the public key is used for encryption only, you can share it securely. However, since the private key can decrypt encoded data, it must be kept secret to ensure only the intended recipient has access.