Checker Bcrypt
Fast, accurate and free online checker bcrypt tool running directly in your browser.
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1Enter data
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3Get the result
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Other tools you may find usefulBcrypt hash verification – secure storage of user passwords
The security of user data in web applications is an absolute priority. One of the most important rules of cybersecurity is that passwords should never be stored in a database in plain text. In the event of a data breach, the burglar would immediately have access to all user passwords. To prevent this, passwords are hashed (hashed) using one-way cryptographic functions. The most popular, proven and widely recommended standard in the IT industry is Bcrypt. Our Bcrypt online hash verifier and tester allows you to safely check the correctness of your password in relation to your hash.
Bcrypt is a one-way function, which means that given the hash itself (e.g.$2y$12$R9h...), it cannot be decrypted (decoded) to a clean password using any algorithm. Verification involves re-hashing the entered password using the same salt and comparing the results. Our tool allows you to check this mechanism for educational and testing purposes, without saving entered passwords on the server.
Bcrypt hash recording structure
The generated Bcrypt hash always consists of 60 characters and has a precisely defined structure from which cryptographers can read the algorithm's parameters. The table below shows the anatomy of an example hash:
| Part of the hash | Example fragment | Technical meaning | Purpose / Function in the algorithm |
|---|---|---|---|
| Algorithm ID | $2y$or$2a$, $2b$ |
Specifies the version of the Bcrypt scheme used for hashing. | Ensuring backward compatibility when library standards change. |
| Cost Factor | 12(two digits) |
The number of iterations of the algorithm expressed as a power of two (\(2^{12} = 4096\) rounds of the Blowfish cipher). | Allows you to slow down the processor during brute-force attacks. |
| Salt | R9h/cIPzJuaXvWCnFv1e2e(22 characters) |
Random string of characters unique to each individual password. | Protects against Rainbow Tables attacks - two identical passwords give different hashes. |
| Proper Hash (Checksum) | OdBp2J1eL1eD321F5a7201c...(31 characters) |
Blowfish encrypted result value after multiple processing. | Used for final comparison with the password entered during login. |
Why is Bcrypt resistant to brute-force attacks?
Unlike very fast hash functions such as MD5, SHA-1 or SHA-256, Bcrypt is intentionally designed to be computationally slow:
- Adaptive algorithm:Bcrypt allows for a smooth change in the computational cost (Cost Factor). As the power of processors and graphics cards increases, administrators can increase the cost (e.g. from 10 to 12 or 14), which makes the calculation of one hash take more time.
- Slowing down brute-force attacks:It takes the CPU about 100-300 milliseconds to hash one password with Bcrypt. For a single user login, this delay is negligible. However, for a hacker trying to check billions of combinations per second (brute-force), this delay makes the attack completely uneconomical in terms of time and power consumption.
- Resistance to Rainbow Tables:Thanks to the built-in, automatically generated 22-character salt, even if a thousand users set the same password (e.g. "123456"), each of them will receive a completely different hash record in the database. The hacker cannot use a ready-made database of previously calculated hashes.
How to securely check and verify a Bcrypt hash?
To check if your forgotten password matches your saved hash, follow these steps:
- Paste your hash:Enter your 60-character hash (usually starting with
$2) in the designated field of the form. - Enter the test password:Enter the password you suspect to be the source of this hash.
- Run verification:The tool will extract the salt and cost from the pasted hash, hash the entered password with the same parameters and compare the results.
- Local security:Our tester uses JavaScript libraries, which means that verification takes place entirely locally in your browser. The password is not sent to the server, which guarantees full data security.
Frequently asked questions (FAQ)
Is it possible to recover the original password from a Bcrypt hash?
No. Bcrypt is a one-way hash function, which means that there is no algorithm or decryption key to reverse the process and read the password. The only way to find a password is to check all combinations one by one (brute-force) or the dictionary method.
What is the difference between hashing and encryption?
Hashing is a one-way process - the input is transformed into a unique fixed-length hash and the input cannot be recovered from it. Encryption is a two-way process - data is locked with an encryption key, but with the appropriate decryption key, it can be fully decrypted to its original form.
What Cost Factor is currently recommended?
Currently, the safe standard for production systems is considered to be cost 10 or 12. This provides an optimal balance between security (hash generation time approx. 100-200 ms) and server performance when handling multiple login requests simultaneously.
What is the difference between Bcrypt and Argon2?
Bcrypt is a proven standard based on the Blowfish cipher. Argon2 (winner of the Password Hashing Competition in 2015) is a more modern function that, in addition to calculation time, allows you to configure RAM consumption (it is resistant to dedicated ASIC systems used by hackers to crack passwords).
Are md5 and sha1 password safe?
Definitely not. The MD5 and SHA-1 functions have been cracked and are extremely computationally fast. A modern home computer can generate billions of MD5 hashes per second, which allows a hacker to crack a simple password in a fraction of a second using the brute-force method.