How to get the original string from a HashCode byte[]?

[gg]

Hi, Dear All,
Please see the following code:

SHA1 sha1 = SHA1.Create();
string str="1234";
byte[] m_str = sha1.ComputeHas h( Encoding.Unicod e.GetBytes( str) );
.....

I want to know how to get the original str -"1234" from m_str?

Thanks

[Roman S. Golubin]

Hi, gg

SHA1 sha1 = SHA1.Create();
string str="1234";
byte[] m_str = sha1.ComputeHas h( Encoding.Unicod e.GetBytes( str) );
....

I want to know how to get the original str -"1234" from m_str?

It is imposible to restore the data from the hash.

Your must store str valiable separate...

Look for sample at
http://msdn.microsoft.com/library/de...redentials.asp

[Nick Malik [Microsoft]]

"gg" <mx*****@hotmai l.com> wrote in message
news:%2******** ********@tk2msf tngp13.phx.gbl. ..

Hi, Dear All,
Please see the following code:

SHA1 sha1 = SHA1.Create();
string str="1234";
byte[] m_str = sha1.ComputeHas h( Encoding.Unicod e.GetBytes( str) );
....

I want to know how to get the original str -"1234" from m_str?

Thanks

Can't be done. If you want the original string, don't use a hash function.
Use private key encryption.

--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik

Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--

[Jon Skeet [C# MVP]]

gg <mx*****@hotmai l.com> wrote:

Please see the following code:

SHA1 sha1 = SHA1.Create();
string str="1234";
byte[] m_str = sha1.ComputeHas h( Encoding.Unicod e.GetBytes( str) );
....

I want to know how to get the original str -"1234" from m_str?

Hashing is particularly designed to be a one-way process. If you want a
two-way process, look at the various symmetric or asymmetric
encryption/decryption algorithms in the System.Security .Cryptography
space.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too