BCrypt is an adaptive cryptographic hash function for passwords. It incorporate a salt to protect against rainbow table attacks and is also an adaptive hash - over time it can be made slower and slower so it remains resistant to specific brute-force search attacks against the hash and the salt.
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“Official statement” on php.net : CRYPT_BLOWFISH is strongest hash algorithm. Why?
First: I asked this question on stackoverflow and was kindly asked to post this here again. See the original question here.
According to the [early] doc pages of the new PHP 5.5 password ...
5
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1answer
87 views
Is the execution time for bcrypt independent of the length of the input string?
Is the execution time for bcrypt independent of the length of the input string?
i.e.
Should the execution time of
bcrypt.hashpw('input_string', bcrypt.gensalt(12))
and
...
2
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0answers
55 views
Knowing a valid salted hash for an unknown secret, is it possible to compute another valid hash? [migrated]
H(s,r)=d is a function that hashes the string s with a salt r, giving the result d.
Hashing functions are not injective, so there isn't a reverse function H'(d,r)=s.
Therefore to prove that d is a ...
198
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9answers
20k views
Is my developer's home-brew password security right or wrong, and why?
Our developer, let's call him 'Dave', insists on using a home-brew script for hashing passwords. See Dave's proposal below.
We have already researched and adopted an industry standard protocol using ...
18
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5answers
713 views
Is it possible to increase the cost of BCrypt or PBKDF2 when its already calculated and without the original password?
I just wanted to know if you can increase the cost (iterations) of those two algorithms off-line.
I want to increase the cost every year of my users passwords.
One solution is to recalculate them ...
20
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8answers
1k views
Why improvising your own Hash function out of existing hash functions is so bad
I'm afraid I'll have tomatoes thrown at me for asking this old question, but here goes.
After reading that cooking up your own password hash out of existing hashing functions is dangerous over and ...
7
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1answer
394 views
Insecure versions of crypt hashes
I read at crackstation not to use these variants of bcrypt* ($1$, $2$, $2a$, $2x$, $3$),but I've used bcrypt ($2a$) in various sensitive implementations recently.
Can any security expert clarify why ...
4
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2answers
2k views
Recommended # of rounds for bcrypt
What is nowadays (July 2012) the recommended number of bcrypt rounds for hashing a password for an average website (storing only name, emailaddress and home address, but no creditcard or medical ...
2
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3answers
194 views
Client-Side Hashing to decrease value of password guessing heuristics
Yes, this is 'yet another client-side hashing' question. But, don't leave yet, I think there is some value here.
I'd like to do something to mitigate the affect on the community as a whole when my ...
-2
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5answers
276 views
Is this password hashing method secure?
I have made a custom hashing method to help make my users' passwords more secure if the database will be leaked.
The encryption method is like this:
A method takes an input of 1 character, gets the ...
6
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2answers
363 views
Production ready bcrypt implementation for .NET
Which, if any, .NET / C# bcrypt implementations are considered suitable for production environments?
I have seen CryptSharp and BCrypt.Net mentioned in answers to other questions but without any ...
6
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6answers
683 views
Client side password hashing
Edit: Updated to put more emphasis on the goal - peace of mind for the user, and not beefing up the security.
After reading through a few discussions here about client side hashing of passwords, I'm ...
3
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1answer
795 views
BCrypt+SHA256 vs PBKDF2-SHA256
From this question, the OP posited taking a user's entered password, running it through BCrypt, then running that through SHA256 to produce a 256-bit password-derived key. (EDIT: To clarify, these two ...
2
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1answer
472 views
Security of bcrypt/sha256 key used with AES to encrypt a file
I'm looking to encrypt files using secure hashing and encryption algorithms in Python. Having used bcrypt in the past, I decided to use it for my passphrase calculator, then pass the output through ...
4
votes
3answers
301 views
How should I choose a difficulty factor for my password hashing function?
Assuming that I'm doing password hashing properly and using bcrypt, scrypt or PBKDF2, how should I go about choosing an appropriate difficulty factor? i.e rounds for bcrypt, iterations for PBKDF2 and ...
3
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3answers
1k views
Is a HMAC-ed password is more secure than a bcrypt-ed or scrypt-ed password?
Given an option , which one should I choose , a HMAC for storing a password securely or a bcrypt or scrypt library?
2
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2answers
424 views
safe to use jBCrypt and recommend it to my organization?
I'd like to recommend to my fellow developers that we all use bcrypt to hash stored passwords. We all use java and I hesitate to recommend jBCrypt only because its latest version number (0.3) ...
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3answers
1k views
Is bcrypt better than scrypt [duplicate]
Possible Duplicate:
Do any security experts recommend bcrypt for password storage?
I'm no security expert and do not pretend to be that's why I'm asking here. I write many PHP based ...
20
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1answer
2k views
Are there more modern password hashing methods than bcrypt and scrypt?
This question made me start thinking about password hashing again. I currently use bcrypt (specifically py-bcrypt). I've heard a lot about PBKDF2, and scrypt.
What I'm wondering is if there are any ...
3
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6answers
279 views
Is there a table that compares hashing algorithms by speed, relatively (machine independent)
As far as I understood*, one of the major criteria when choosing a password / salt hashing algorithm is it's speed. To prevent brute force attacks, a slower algorithm is better (and also makes it more ...
2
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4answers
239 views
Login form authentication logic
I am building my login form action, and I want to make sure my logic is solid and as secure as possible.
1.) First I check if the provided e-mail address exists in database, if not, I show a generic ...
7
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4answers
920 views
Challenging challenge: client-side password hashing and server-side password verification
We have a website where users need to log in to access privileged information. Obviously we are using SSL, but I also want to avoid plaintext passwords from accidently ending up in server logs, or ...
2
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1answer
172 views
Is there a better way to take advantage of current 'approved', 'proven', and memory/cpu-expensive algorithms while using salts and peppers?
I've read about the concepts presented in these two questions:
Pre-hash password before applying bcrypt to avoid restricting password length
Would it make sense to use Bcrypt and PBKDF2 together?
I ...
3
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1answer
173 views
Base64 encode diffences in BCrypt implemenations
I was reading the source code of several BCrypt implementations and found that two common c implementations have a difference in their base64 encoding of for the salt.
What is the effect, if any, of ...
7
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2answers
281 views
BCrypt's 72-character limit and using it as a general digest algorithm
Goal: have token/cookie-based authentication that doesn't require keeping sessions on the server
TL;DR: What, if any, is the accepted mechanism to work around the 72-character limitation of BCrypt?
...
9
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1answer
779 views
How to apply a pepper correctly to bcrypt?
For hashing passwords in a database, i would like to add a pepper to the hash function. Of course this pepper will be additionally to the unique salt.
The reason why i want to add a pepper is, that ...
0
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0answers
64 views
Recomended hash algorithm [duplicate]
Possible Duplicate:
How to securely hash passwords?
Do any security experts recommend bcrypt for password storage?
What would you choose between:
PBKDF2 SHA256 (270,000 iterations)
...
6
votes
3answers
252 views
Is it secure to use bcrypt-generated salt in cookie to serve as token in place of a password?
I have a (hobby) web site that runs only on SSL. The site does not deal with finances, social security numbers, or anything of that level of importance. However, I'd like to secure it as much as ...
12
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3answers
537 views
Should you care about DoS attacks if your server is using bcrypt?
(I just asked this question on "cryptography SE" and was suggested to ask it here instead)
EDIT I just realized my question is mostly a dupe of: Prevent denial of service attacks against slow hashing ...
5
votes
3answers
340 views
bcrypt: random salt vs computed salt
I'm pretty new to the whole password hashing business, so I might be missing something obvious.
I was looking at the bcrypt algorithm, in particular BCrypt.Net, and I was wondering if it wouldn't be ...
1
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2answers
216 views
Scrypt + Bcrypt = cascade hashing
I've read here that hashing with differents algorithms would be a good idea.
Can you confirm that?
In your experience, is it useful and safe? Does it entail any security holes?
4
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3answers
362 views
Trying to understand password hashing
I am trying to get a grasp of password hashing. Back in the days it seemed so simple, just MD5(password + salt) and you are done. Then md5 was proven to have collisions so people started moving to ...
7
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1answer
619 views
Would it make sense to use Bcrypt and PBKDF2 together?
I've read various opinions about whether Bcrypt or PDBKF2 is a better key derivation hashing method. The answer seems to depend on a lot of complicated factors that are not easy to analyze. Would ...
2
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1answer
180 views
PCI-DSS and salt storage
PCI-DSS states the following:
3.5 Protect any keys used to secure cardholder data against disclosure and misuse
I have a service which stores a salted bcrypt hash of the user's PAN. Assuming the ...
5
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1answer
1k views
Does NIST really recommend PBKDF2 for password hashing?
We hesitated between BCrypt and PBKDF2 for password hashing. In many forums and blogs people say something like "In their Special Publication SP 800-132 NIST basically recommends using PBKDF2 for ...
2
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1answer
89 views
What is the meaning of 'adaptative' and 'over time it can be made slower' in the context of the bcrypt algorithm?
I'm reading the wikipedia definition about bcrypt but I don't understand the meaning of 'adaptative' and 'over time it can be made slower'. Can someone explain what they mean in this situation?
2
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1answer
1k views
Is BCrypt enough when saving a password into a database?
In order to allow users to connect to my website, I encrypt their password using BCrypt since it is one of the slowest algorithms to decrypt (making a compromised database longer to be decrypted).
...
