Encrypt and Decrypt password

bekim · August 18th, 2004, 09:06 AM

Hello
I am trying to take passwords and encrypt it before sending to database. Then store in database as encrypted. Then when need to retrieve password, I want to get encrypted password and decrypt before displaying to user.

I know about 2 types MD5 and SHA1.
The only example I found was using FormsAuthentication.HassPasswordForStoringInConfig File.

Can I use this as long as I don't store it in config file?

But I realized there is no example on how to decrypt this.

Also I noticed in FormsAuthentication there is Encrypt and Decrypt method.

Can anyone give me a simple code as example?

Hal Levy · August 18th, 2004, 09:19 AM

MD-5 Encryption isn't reversable...(I belive the same is true for SHA-1).
You would encrypt the PW and store it. When the user enters a password, you would encrypt that and compare the encypted strings. if they match, the source PW matches...

Hal Levy
Web Developer, PDI Inc.

NOT a Wiley/Wrox Employee

bekim · August 18th, 2004, 10:37 AM

You can't decrypt SHA1 of MD5?

When user forget their passwords how do I get that password if these encryption types are no decryptable???

What is the standard way to store passwords user enter to register?
My guess was that the password gets stored encrypted but when they forget it then I would have to decrypt it.

Hal Levy · August 18th, 2004, 10:41 AM

Ok.. I belive I said that... You can't decrypt them.. Therefore, you couldn't get their passwords....

Many sites store plaintext.. others store encrypted.. create new temp passwords and email them to people who forget their passwords and then they can reset to something they know.. others have reminder questions that will cause people to possibly remember their account.. there are many tools sites have used.. visit a few :)

Hal Levy
Web Developer, PDI Inc.

NOT a Wiley/Wrox Employee

bmains · August 18th, 2004, 11:05 AM

Hey,

You don't want to store it using a hash then. Hashing is a one-way operation. Use another type of encryption that uses a public key/private key. Using these keys, this is how you would decrypt the data.

Brian

bekim · August 18th, 2004, 06:43 PM

Where can I find a simple example of this encryption that uses a public key/private key?

I can't find a example in a book.
Thank you all

mateenmohd · August 19th, 2004, 03:35 AM

visit following site, it will help you.

http://pajhome.org.uk/crypt/md5/

regards.

bmains · August 19th, 2004, 07:29 AM

Hey,

Look in the MSN for the System.Security.Cryptography namespace.

Brian