Question 1

What is Bcrypt?

Accepted Answer

Bcrypt is a password-hashing function designed specifically to be slow and computationally expensive. This makes it highly resistant to brute-force and rainbow table attacks compared to fast hashes like MD5 or SHA-256.

Question 2

What are 'Salt Rounds' (Cost Factor)?

Accepted Answer

The cost factor (or rounds) determines how many times the hashing algorithm is iterated. A factor of 10 means 2^10 (1024) iterations. Increasing the cost makes the hashing slower, thus defending against faster hardware used by attackers.

Question 3

What is the recommended number of salt rounds?

Accepted Answer

As hardware becomes faster, the recommended cost increases. Currently, a cost factor of 10 to 12 is considered standard and strikes a good balance between security and server performance.

Question 4

Why does the same password generate a different hash every time?

Accepted Answer

Bcrypt automatically generates a unique random 'salt' (a random string of characters) every time it hashes a password. This salt is appended to the password before hashing, meaning the final hash will always be unique even for identical passwords.

Question 5

Is my plain-text password sent to a server?

Accepted Answer

No. The hashing and verification processes are executed completely on your device using JavaScript. Your data remains strictly local and private.

Question 6

How does verification work if the salt is random?

Accepted Answer

The generated salt and the cost factor are both stored securely inside the resulting Bcrypt hash string. During verification, the algorithm extracts the salt from the hash, hashes the provided plain text with that exact salt, and checks if the results match.

Question 7

Can I decrypt a Bcrypt hash back to the password?

Accepted Answer

No. Bcrypt is a one-way hashing function. It is mathematically impossible to reverse the hash to reveal the original password.

Question 8

Why is the generator taking a long time to finish?

Accepted Answer

Bcrypt is intentionally slow. If you select a high cost factor (e.g., 14 or 15), your browser has to perform tens of thousands of complex calculations, which can take several seconds.

Question 9

What do the parts of a Bcrypt hash mean? (e.g., $2a$12$)

Accepted Answer

The `$2a$` indicates the algorithm version. The `$12$` is the cost factor (salt rounds). The remainder of the string contains the 22-character Base64-encoded salt followed by the 31-character encoded hash.

Question 10

Can I use this tool to recover lost passwords?

Accepted Answer

No. Since Bcrypt cannot be decrypted, you cannot retrieve a lost password from the hash. You can only verify if a guessed password is correct.

Bcrypt Hash Generator & Verifier

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