Tell me more ×
Cryptography Stack Exchange is a question and answer site for software developers, mathematicians and others interested in cryptography. It's 100% free, no registration required.
up vote 0 down vote favorite

A Simple question, if i run a string trough the standard md5 encryption function multiple times, does it increase security the more i do it? does it protect against rainbow tables? etc.

share|improve this question
Yes, slightly, use bcrypt or scrypt. $\:$ – Ricky Demer Feb 20 at 8:48
4  
What kind of string? What security goal? This can't be answered if it's so vague. If you hash a password, use a salted password hash, such as PBKDF2, bcrypt or scrypt. If you want a general purpose hash, use SHA-2. – CodesInChaos Feb 20 at 8:55
I am going to close the question until you provide more details as it appears that as it stands, the question is too vague to answer. See CodesInChaos' comment. Edit and flag it and we can look at reopening the question. – mikeazo♦ Feb 20 at 14:19
1  
I don't see how this is vague, he's asking if he runs a string through md5 and then pass the md5 through MD5 would that be safe against rainbow tables. The answer is clearly, Yes. – Ryan McDonough Feb 20 at 14:20
@RyanMcDonough, perhaps against existing rainbow tables, but all it would take is for someone to create new tables that do the same thing. – mikeazo♦ Feb 20 at 18:15
show 1 more comment

closed as not a real question by mikeazo♦ Feb 20 at 14:19

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, see the FAQ.

Browse other questions tagged or ask your own question.