What Are Rainbow Tables?
The rainbow table is a powerful tool to decode passwords. A lot of people on the web are after these passwords. They want access to the password for the criminal activities, or they are experts who want to ensure utmost privacy. Rainbow tables are useful to decode passwords instantly. You do not necessarily want to crack the password for criminal activity. However, it is always useful to have basic knowledge about this process. This will help you understand the need for a strong password.
Why Do We Need Rainbow Tables?
Passwords are stored online after the encoding process. When we enter a password on a website, it does not appear as it is on the server. If the passwords appear in their actual form, it becomes easy for hackers to hack those passwords. They could crack the password and stole your personal information available on the particular account.
If the compromise of the password happens, it can prove disastrous for e-commerce, online banking, or any other online service. That is why online service providers use various encoding methods to secure the data. They encode the passwords of their users to protect them from potential hackers. By doing this, only the hash value of the passwords is visible on the server.
One cannot crack a password through its hash value, even if one knows the crypto function. There is no option to reverse this process. Hackers use another technique called brute force attack to crack the passwords. It is a computer program that keeps guessing the passwords using different character sequences. There is another method that hackers use to crack passwords, they use password dictionaries. These dictionaries are available online and one can get them via the internet. They use this information according to the password they want to access. This saves them time to decode the password, but it is also a complex and very lengthy process.
Rainbow tables are designed by keeping password dictionaries in mind. As we know, password dictionaries are available online. These dictionaries help to crack passwords. Password dictionaries can be very large files, that contain passwords and also their hash values. Sometimes it also contains the encoding methods. Rainbow tables help you to decode your password into plaintext.
How Do Rainbow Tables Work/Used?
It is essential to know about crypto-algorithms to understand the rainbow tables. There are various techniques currently being utilized in the Rainbow tables. We will discuss some of these techniques below:
Encryption Technology
As the cryptographic hash function is under use for a long time in encryption and the related algorithms have been improved from time to time. The encryptions that were impossible to breach have become very vulnerable now. All the methods have one thing in common, they convert the data into its hash value. The hash value is mostly a hexadecimal number with a particular length, and it does not depend on the actual length of the content. It is always a 128-bit hash value. Some properties are important for encryption as given below:
- We will get the same hash value for particular content, and this way the hash value works as a checksum. It does not matter if passwords are identical, because the system only grants access if the hash value is the same.
- The hash value is a unique entity, that is why every input has its unique hash value. This is important to verify the correct password. As we know possibilities of hash values have limits but there is no limit to entries. This can cause some problems but the latest hash functions are coming with a wide range of possibilities to reduce this risk.
- As we know, we cannot reverse the hash value to obtain the real content. This means there is no possibility to decode a hash value. However, the possibility to comprehend these values is always there.
Reduction Function
The hash values are present in the Rainbow tables before an attack happens. It means that the hackers can copy these hash values from Rainbow tables to extract passwords, but these files are large. To minimize storage use, Rainbow tables use a special function to decode the hash value to simple plain texts. This function is called the reduction function. It does not reverse the hash value to create the original value but generates a completely new value.
This new text generates a new hash value, this process is continuous and creates a chain. In the end, only the initial password value and the last hash value is present in the chain. By using these two values and the reduction function, one can determine the remaining values of the password.
What Do Tables Have to Do with Rainbow?
An important question arises in our mind that what is the link between these tables with rainbows? Practically you can use different reduction functions in each step. That helps you to reduce the chances of repetition of hash values in the table and offer better results. However, it makes it difficult to search for appropriate hash combinations and passwords in a chain.
To solve this issue, different reduction functions are marked with different colors. This results in a colorful rainbow. This is why these tables are called Rainbow Tables.
Protection Against Rainbow Tables
It is clear now that hackers can breach the security of your accounts through the Rainbow tables. Therefore, it becomes necessary to take some precautionary measures to avoid any such situation. Users and website authorities both can take measures to avoid these breaches, or at least make it difficult for attackers. We will discuss this below:
User
For users, they can make their password difficult to crack. That is why a strong is necessary. Password should be a combination of letters, numbers, and special characters. This way, it is difficult to crack any passwords no matter if it is a brute force attack or Rainbow tables. Another option is to use a lengthy password; it increases the size of the Rainbow table required to crack the password.
Administrator
Website administrators can also do their bit to protect the data of their users. They should prevent the breach in the first place. The website should use up to date SSL certificates to prevent any attack. A DV SSL certificate helps you reduce the chances of any cyber-attack. All the big brands use up to date SSL certificate to secure their website.