Bcrypt is a widely-used hashing algorithm to securely store passwords used by web applications. Bcrypt is designed in such a way that it is almost impossible to reverse engineer a password from the hash. This makes it difficult to recover lost or forgotten passwords, and sometimes it’s necessary to decrypt the password hash. In this blog, we will provide 4 methods to decrypt a Bcrypt password online. We will also discuss the challenges and limitations of each method, and methods to fix them.
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The Challenge of Decrypting Bcrypt Passwords Online
Bcrypt is designed to be very difficult to reverse engineer a password from a hash. Bcrypt hashes are created with a salt and cost value embedded into the hash. The salt value prevents the use of rainbow tables, and the cost value makes the hash very time-consuming to compute.
This makes it very difficult to decrypt a Bcrypt password online. To decrypt a Bcrypt password, you will need access to the salt value and the cost value used to create the hash. Without them, it can take days, weeks or even months to crack the password.
Method 1: Using Online Password Decryption Tools.
This is the most common method used to decrypt Bcrypt passwords online. There are many online tools that claim to decrypt Bcrypt passwords, but not all of them are safe and reliable. In this method, we will use OnlineHashCrack, an online decryption tool with a reputation for being safe and reliable.
Method:
1. Copy the Bcrypt hash to decrypt.
2. Go to the OnlineHashCrack website.
3. Paste the Bcrypt hash into the input box and select "Bcrypt" from the list of available hash types.
4. Click the "Crack Hash" button.
5. Wait for the tool to decrypt the password.
6. Once the password has been decrypted, it will be displayed on the screen.
Pros: This method is very easy to use and requires no technical skills. It’s also a fast method to get the password.
Cons: This method has security concerns as it involves sharing the password hash online. Also, the decryption tool may not always work.
Method 2: Using Brute-Force Attack.
Brute-Force Attack is a hacking technique where a program tries all possible combinations of characters until the correct password is found. This is a time-consuming method and can take days, weeks or even months to crack the password. In this method, we will use a program called Hashcat to perform a Brute-Force Attack.
Method:
1. Install Hashcat on your computer.
2. Open a command prompt and navigate to Hashcat’s directory.
3. Type the command: hashcat -m 3200 -a 3 /path/to/bcrypt/hash ?a?a?a?a?a?a?a?a
-m 3200 indicates we are using the Bcrypt hash algorithm.
-a 3 indicates we are using a Brute-Force Attack.
/path/to/bcrypt/hash represents the location of the Bcrypt hash to decrypt.
4. Wait for Hashcat to brute-force the password.
5. Once the password has been decrypted, it will be displayed on the screen.
Pros: This method can be performed offline, which means it’s more secure than using online decryption tools. Also, it’s effective in cracking simple passwords.
Cons: This method is time-consuming and can take days, weeks or months to crack complex passwords.
Method 3: Using Rainbow Tables.
Rainbow Tables are pre-computed tables that contain a large number of password hashes and their corresponding passwords. Rainbow Tables can be very effective in cracking simple passwords. In this method, we will use a program called RainbowCrack to decrypt a Bcrypt password.
Method:
1. Download the Bcrypt Rainbow Tables from the internet.
2. Install RainbowCrack on your computer.
3. Open a command prompt and navigate to RainbowCrack’s directory.
4. Type the command: ./rtgen -t bcrypt -f plaintext.txt -l hashes.txt
This command will generate a set of Rainbow Tables based on the plaintext.txt file and store the Bcrypt hashes in the hashes.txt file.
5. Type the command: ./rcrack -h /path/to/bcrypt/hash -t hashes.txt
This command will use the Rainbow Tables to decrypt the Bcrypt hash.
6. Wait for the tool to finish cracking the password.
7. Once the password has been decrypted, it will be displayed on the screen.
Pros: This method is relatively fast and effective in cracking simple passwords.
Cons: This method is not effective in cracking complex passwords as it requires a lot of disk space to store Rainbow Tables.
Method 4: Using John the Ripper.
John the Ripper is a popular password cracking tool used by many security researchers and hackers. It is capable of cracking many types of passwords, including Bcrypt. In this method, we will use John the Ripper to decrypt a Bcrypt password.
Method:
1. Install John the Ripper on your computer.
2. Open a command prompt and navigate to John the Ripper’s directory.
3. Type the command: ./john --list=formats
This command will display a list of available password formats, including Bcrypt.
4. Type the command: ./john /path/to/bcrypt/hash
This command will use John the Ripper to crack the Bcrypt hash.
5. Wait for the tool to finish cracking the password.
6. Once the password has been decrypted, it will be displayed on the screen.
Pros: This method is fast and effective in cracking simple passwords.
Cons: This method is not effective in cracking complex passwords.
Why Failed to Decrypt Bcrypt Passwords Online
There are several reasons why decrypting Bcrypt passwords online can fail:
1. The password is too complex, making it difficult to crack.
2. The online decryption tool is unreliable or not secure.
3. The hash has been salted and the salt value is not available.
4. The cost value used to create the hash is not available.
Fixes:
1. If the password is too complex, try using a program to perform a Brute-Force Attack or use Rainbow Tables.
2. Always use a trusted online decryption tool.
3. Make sure to keep a record of the salt value and cost value used to create the hash.
FAQs
Q. Can I use these methods to decrypt any Bcrypt password?
A. No, these methods can only be used to decrypt Bcrypt passwords where you have access to the salt value and cost value used to create the hash.
Q. Is it legal to decrypt someone else’s Bcrypt password?
A. No, it is illegal to decrypt someone else’s password without their permission.
Q. Is there a risk of damaging the password hash while decrypting it using these methods?
A. No, there is no risk of damaging the password hash while decrypting it using these methods.
Q. Is it possible to use these methods offline?
A. Yes, Method 2 and Method 4 can be used offline.
Q. Can these methods be used to decrypt other hash types?
A. Yes, these methods can be used to decrypt other hash types, but the hash type must be supported by the program being used.
Q. Can I use these methods to decrypt Bcrypt passwords in bulk?
A. Yes, these methods can be used to decrypt Bcrypt passwords in bulk, but it may take longer to crack each password. You will need to write a program to automate the process.
Conclusion
Decrypting Bcrypt passwords online can be very challenging due to the complexity of the hashing algorithm. We have presented 4 methods to decrypt Bcrypt passwords online, including the use of online decryption tools, Brute-Force Attack, Rainbow Tables and John the Ripper. Each method has its pros and cons, limitations and challenges. We hope this blog has been helpful in guiding you through the process of decrypting Bcrypt passwords online.