To access our digital accounts, we often need passwords or passphrases. But just as keys and locks can be weak, not all passwords are secure.
To strengthen your online defenses, security experts have developed a range of techniques to make passwords more secure. These methods include hashing, salting, peppering, and key stretching among others. Let’s explore the importance of key stretching and how it can significantly boost your online security.
What Is Key Stretching?
Key stretching is a cryptographic technique used to enhance the security of passwords and passphrases, especially in scenarios where the original password may not have sufficient randomness or length to resist various types of attacks, such as brute force or dictionary attacks. Key stretching makes a password or key stronger and more secure by performing multiple hashing processes on it.
Key stretching is also known as key strengthening, and it typically involves taking a relatively weak and short password or cryptographic key and applying a cryptographic function or algorithm to produce a stronger and longer key. This is done over and over until a desired key is attained. The idea is to make it computationally expensive and time-consuming for an attacker to recover the original key, even if they have access to a hashed or encrypted version of it.
Key stretching plays a crucial role in applications that demand a high level of security, such as online accounts, financial transactions, and data protection. It is a key component in ensuring the safety of stored passwords and cryptographic keys, which ultimately translates to safeguarding user data and maintaining trust.
How Does Key Stretching Work?
As we’ve discussed in the previous section, key stretching converts a weak password into a more robust and secure password.
Let’s illustrate this with a straightforward example: imagine your password is something as commonplace as “iloveyou.” It’s no secret that such a password is like an open door for attackers, as it’s often found in brute-force wordlists and dictionary tables. In fact, it wouldn’t take more than 30 seconds for anattacker to crack it and gain access to your account. This is where the concept of key stretching comes into the picture.
Key stretching takes this vulnerable password and hashes it to create something longer and more complex. For instance, “iloveyou” transforms into “e4ad93ca07acb8d908a3aa41e920ea4f4ef4f26e7f86cf8291c5db289780a5ae.” But the process doesn’t stop there.
When this new password is hashed again, it becomes “bc82943e9f3e2b6a195bebdd7f78e5f3ff9182ca3f35b5d415cf796ab0ce6e56.” And one more time, we hash it to produce “46e95d6374c00c84e4970cfe1e0a2982b2b11b1de9343a30f42675a2154a28f5.” You can do this as many times as you wish.
Now, you might be wondering if you need to roll up your sleeves and write all this code yourself. The good news is that you don’t have to! There are already libraries available for key stretching that can do the heavy lifting for you. Some popular key stretching algorithms include PBKDF2, scrypt, Argon2, and bcrypt. Of these, bcrypt and PBKDF2 are the most widely recognized.
bcrypt applies the blowfish cipher to conduct multiple rounds of hashing, making it a robust choice for securing your passwords. Meanwhile, PBKDF2, or “Password-Based Key Derivation Function 2,” is another solid option for enhancing the security of your keys or passwords. These tools ensure that even the feeblest of passwords can be transformed into formidable barriers against unauthorized access.
Key Stretching vs. Salting
Key stretching and salting are both vital techniques in the realm of password security, each playing a unique role in enhancing the strength of passwords.
Key stretching involves subjecting your passwords to multiple rounds of hashing, effectively turning a weak password into a more secure version. The more rounds you perform, the more secure your password becomes. Salting, on the other hand, provides an extra layer of defense.Password saltingentails adding a distinct string of characters to your password before applying the hashing process. This added complexity elevates the resilience of your password.
The amazing thing is that these two techniques can be used together to enhance the strength of a password. The salt isn’t an afterthought; it’s integrated from the outset, enhancing the weak password before it undergoes the hashing process. In essence, key stretching and salting are like a tag team, collaborating to fortify and safeguard your sensitive information with an extra layer of protection.
Why Is Key Stretching Important?
Key stretching is commonly used in password-based encryption and authentication systems. It helps mitigate the risk of weak or easily guessable passwords by making it computationally expensive for attackers to recover the original password or key, even if they have access to hashed or encrypted versions of it. This makes it an important component of security in various applications, such as protecting stored passwords and securing cryptographic keys.
Here are some reasons why key stretching is important and should be implemented:
Secure Your Assets Using Password-Strengthening Techniques
Passwords are the first line of defense, and you can’t always rely on users to choose secure passwords for their accounts. Moreover, attackers are becoming increasingly sophisticated, even when dealing with seemingly secure and popular passwords.
To stay ahead of the game, it’s crucial to go that extra mile and implement advanced techniques such as key stretching, salting, and peppering. These methods are indispensable for transforming weak passwords into fortified shields against potential threats, ensuring that your data and accounts remain safeguarded.
