What is the number of rounds in bcrypt?
For bcrypt, the number of rounds is also included. This facilitates adapting the password verification time to increasing processor speed. Currently, the default number of rounds for a normal user is 26, and 28 for ``root.
With "salt round" they actually mean the cost factor. The cost factor controls how much time is needed to calculate a single BCrypt hash. The higher the cost factor, the more hashing rounds are done. Increasing the cost factor by 1 doubles the necessary time.
Salting a password
The salt gets automatically included with the hash, so you do not need to store it in a database.
Hashing types make the most difference here, with bcrypt encrypted passwords requiring over 22 years to crack, according to our testing.
bcrypt is a very hard to crack hashing type, because of the design of this slow hash type that makes it memory hard and GPU-unfriendly (especially with high cost factors).
bcrypt has a maximum length input length of 72 bytes for most implementations. To protect against this issue, a maximum password length of 72 bytes (or less if the implementation in use has smaller limits) should be enforced when using bcrypt.
You can't decrypt but you can BRUTEFORCE IT...
I.E: iterate a password list and check if one of them match with stored hash.
TL;DR; SHA1, SHA256, and SHA512 are all fast hashes and are bad for passwords. SCRYPT and BCRYPT are both a slow hash and are good for passwords. Always use slow hashes, never fast hashes.
"`bcrypt` was designed for password hashing hence it is a slow algorithm. This is good for password hashing as it reduces the number of passwords by second an attacker could hash when crafting a dictionary attack. "
By executing a round of hashing, the crypt algorithm makes at least a one bit change to the message, resulting in a completely new hash. If the hash algorithm didn't have strong collision resistance, then yes, it would be possible to have multiple rounds that don't change the hash much.
What is work factor in BCrypt?
When BCrypt was first designed in 1999, it was created using a work factor of 6, and a password would be hashed in roughly ~0.5 to 1 second. Now, in 2015, a work factor of 10 is considered standard, and some people advocate a work factor of 12.
A lot of your research is correct and still applies in 2021, so it is still secure to use BCrypt (which usually generates its own random salt for each password). Good password hashing algorithms are Argon2, SCrypt and BCrypt, they all offer a cost factor which controls the necessary time.
BCrypt Algorithm is used to hash and salt passwords securely. BCrypt permits building a password security stage that can advance nearby hardware innovation to guard against dangers or threats in the long run, like attackers having the computing power to guess passwords twice as quickly.
