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Algorithms

 
GeneralWholesale Sources Pin
Andrew Dudley16-Dec-11 19:46
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forex platform30-Nov-11 21:09
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QuestionDirichlet problem for the unit circle code Pin
Chesnokov Yuriy27-Nov-11 17:19
professionalChesnokov Yuriy27-Nov-11 17:19 
AnswerRe: Dirichlet problem for the unit circle code Pin
Roger Wright9-Dec-11 4:03
professionalRoger Wright9-Dec-11 4:03 
QuestionSafely storing passwords Pin
Bernhard Hiller15-Nov-11 20:55
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AnswerRe: Safely storing passwords Pin
Alan Balkany22-Nov-11 4:06
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canlel9-Dec-11 0:08
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AnswerRe: Safely storing passwords Pin
OriginalGriff9-Dec-11 1:06
mveOriginalGriff9-Dec-11 1:06 
You have probably solved this by now, but since you got a recent response, I thought I woudl add my two pence worth.

I tend to use the UserID as the salt - not the username, but the unique value I assign in the database table (personally, I tend to use GUIDs for these) and take an SHA hash of the combined id and password. I then store the hash as a comparison value in the DB.

If you don't use some salt, then it is relatively easy to spot common passwords (they would all have the same value as a hash) and if you crack one of them (by looking at the hash for common passwords) you have access to all those accounts. For example, if 50% of your accounts have the same hash, change your password to "password" and see what hash your account has. If it matches, then you know the password for 50% of the accounts.

MD5 does indeed have some problems - it is officially classed as "broken" and should not be used for new designs. What that means is that there is a way to get a valid input (not necessarily the original input, but valid) from the MD5 hash value. It isn't a real problem, but with security it is a good idea to avoid it as a result. SHA is currently unbroken, and you should use that - the .NET cryptography namespace includes SHA in several sizes.
Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water

QuestionLearning software design patterns Pin
Hypermommy9-Nov-11 22:26
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PIEBALDconsult10-Nov-11 1:54
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QuestionA small exercise Pin
PIEBALDconsult9-Nov-11 13:25
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Luc Pattyn9-Nov-11 14:34
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Luc Pattyn9-Nov-11 14:37
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PIEBALDconsult9-Nov-11 14:37
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BobJanova10-Nov-11 1:30
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AnswerRe: A small exercise Pin
Roger Wright9-Dec-11 4:26
professionalRoger Wright9-Dec-11 4:26 
QuestionSearching for algorithm for text file comparison (with list of differences) Pin
xtomiii9-Nov-11 10:48
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AnswerRe: Searching for algorithm for text file comparison (with list of differences) Pin
Luc Pattyn9-Nov-11 11:46
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PIEBALDconsult9-Nov-11 13:18
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AnswerRe: Searching for algorithm for text file comparison (with list of differences) Pin
Luc Pattyn9-Nov-11 13:33
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GeneralRe: Searching for algorithm for text file comparison (with list of differences) Pin
PIEBALDconsult9-Nov-11 13:34
mvePIEBALDconsult9-Nov-11 13:34 
GeneralRe: Searching for algorithm for text file comparison (with list of differences) Pin
Luc Pattyn9-Dec-11 6:31
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QuestionAudio processing Pin
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