Introduction

The entire world has gone digital, and nowadays, it is easy to become victim of cyber-attacks. That’s why it is always better to remain vigilant and alert.

While other physical safety protocols may be implemented to secure your data, encryption acts as an important security layer to prevent data leaks. So, in case an intruder gets access to the server and steals the data, the intruder will not be able to get the original data, at least not without the decryption key.

However, if simple encryption methods are used, an intruder can easily decrypt the data. That’s why advanced encryption methods should be used to ensure that the third party cannot decrypt the method using brute-force attacks, computational shortcuts, or other cryptographic analysis techniques that could compromise the information.

In our previous Cryptography blogs series, we looked at Cryptography Basics, Advanced Techniques, RSA PKI and HTTPS. In this blog, let’s summarize the key takeaways from the earlier blogs to strengthen your data security and mitigate the threats.

Key Takeaways

1. Always Protect Data at Rest and Data in Transit

Protecting data in both states—at rest (when stored on disk) and in transit (when transmitted over a network)—is essential to safeguarding sensitive information. It’s important to encrypt all the sensitive information including PII (Personally Identifiable Information) at rest. Some examples of PII include Name, Address, Social Security Number, Aadhaar Number, PAN Number, Passport Number, Credit/Debit Card Number etc., For data in transit, it’s important to ensure that all communication between client and server happens via HTTPS.

2. Never Roll Out Your Own Cryptography Method

For most use cases, It’s important to use trusted encryption methodologies/libraries and not create our own custom encryption logic. Even a minor mistake in creating custom cryptographic algorithms can lead to vulnerabilities. That’s why it is best to trust well-established cryptographic libraries that have undergone rigorous testing and used by many other organizations as well, as they have undergone extensive testing by professionals to identify any vulnerabilities.

3. Use AES-256 for Symmetric Key Encryption

Symmetric key encryption algorithms include AES (Advanced Encryption Standard), DES (Data Encryption Standard), IDEA (International Data Encryption Algorithm), Blowfish (Drop-in replacement for IDEA or DES), and Rivest Cipher (RC 4, 5, and 6).

AES uses a cipher block of 128 bits, but there are different key lengths with AES-128, AES-192, and AES-256. AES-256 is preferred because:

1. It cannot be easily cracked through brute-force attacks. Although it can be, it will still take 10-18 years to do so if your cryptographic keys aren’t shared with anyone.
2. It is based on symmetric keys, which ensure faster encryption, is easy to manage, requires less computational power to run, and is suitable for encrypting large volume of data.
3. It ensures that the infrastructure breach doesn’t turn into data breach. Your data remains safe from data theft and ransomware attacks.

If you consider what it will take to decode AES-256 encrypted messages, an attacker would have to try 2^256 combinations using highly powerful computers. Decrypting AES-256 is beyond the capabilities of even quantum computers.

4. Use RSA for Key Exchange in Difficult Scenarios

In scenarios where a secure key exchange is challenging or when you want to avoid revealing the symmetric encryption key, RSA (Rivest–Shamir–Adleman) is an excellent choice. RSA is an asymmetric encryption algorithm that enables secure key exchange by leveraging a pair of keys: a public key to encrypt data and a private key to decrypt it. Because RSA can be used to securely exchange AES keys, it is often used in combination with AES-256 (Hybrid Encryption) to protect both data and the keys used to encrypt it.

5. Use Padding

Padding adds extra bytes to the plaintext before encryption to ensure it meets the required length for the encryption algorithm. Padding prevents patterns from forming, making data more resistant to certain types of attacks. For instance, padding is essential in block cipher modes like AES-CBC, where each block needs to be of a specific length. Adding padding helps obscure the true structure of the original data, which makes it harder for attackers to decipher encrypted information.

6. Use Salt for Hashing

Salting involves adding random data (a salt) to the input of a hash function. This practice is vital, especially in password hashing, because it ensures that identical inputs do not produce the same hash. Adding salt to each input makes it more challenging for attackers to use precomputed tables, like rainbow tables, to reverse hashes into original values. This step is a fundamental layer of security when storing hashed passwords and sensitive data.

7. Avoid Using the Same Salt Value

Each hash operation should use a unique salt. Reusing salt values across multiple pieces of data reduces the effectiveness of the salt, making it easier for attackers to exploit patterns. Unique salts make each hashed value distinct, even for identical data inputs. Random, one-time salts provide the highest security, making it exceedingly difficult for attackers to find or predict them.

8. Longer Key Length, Padding, and Salt Values are Better

In general, longer key lengths, padding, and salt values offer greater security, as they require exponentially more effort to crack. A longer key length in encryption (e.g., 256-bit keys in AES) increases the difficulty of brute-force attacks, while larger padding and salt values add layers of complexity. However, these values should be selected based on security requirements and performance needs, balancing strength with system efficiency.

9. Use Cloud Services like KMS and Key Vault for Key Management

Cloud-based key management solutions, such as AWS Key Management Service (KMS) and Azure Key Vault, offer secure and scalable methods to manage encryption keys. They provide centralized control, automated key rotation, and hardware-backed security, making it easier to meet security compliance and protect sensitive data. Leveraging these services reduces the risk of improper key handling and access management, allowing organizations to maintain secure encryption practices.

10. Always implement HTTPS for Secure Communication

HTTPS is a necessity for securing communications between a user’s browser and your website, encrypting data in transit to prevent interception by attackers. Implementing HTTPS ensures that sensitive information, like login credentials and payment details, is transmitted securely, protecting both users and the website from data theft and man-in-the-middle attacks.

Wrapping Up

We looked at the Key Takeaways from our Cryptography Blogs Series and as developers, it’s important to keep these best practices in mind, when securing data in your application.