How to decrypt sha1 encrypted string C#

Question

I've encrypted a string(hello) using SHA1 using below code. Please guide me to decrypt this string.

SHA1Managed sha1 = new SHA1Managed();
byte[] hash = sha1.ComputeHash(Encoding.UTF8.GetBytes("hello"));
StringBuilder sb = new StringBuilder(hash.Length * 2);
foreach( byte b in hash)
{
    sb.Append(b.ToString("x2"));
}
string result = sb.ToString();

While searching in internet, I didn't find decryption using SHA1, even in MSDN. Kindly guide me.

Consider doing a little research on what SHA1 and in general what hash functions **are** and waht they are used for. — zaph, Feb 22 '16 at 14:02

score 8 · Answer 1 · edited May 23 '17 at 12:23

8

SHA is a hashing method. It is not an encryption. Therefore, it can not be reversed.

Fundamental difference between Hashing and Encryption algorithms

edited May 23 '17 at 12:23

Community

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answered Feb 22 '16 at 12:25

Dave Bush

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score 5 · Answer 2 · answered Feb 22 '16 at 12:23

5

SHA-1 is an digest algorithm, not an encryption algorithm. You can not reverse a digest algorithm like SHA-1.

The only way would be to brute force all potential inputs and see if you get the same result.

answered Feb 22 '16 at 12:23

Robert

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Ivan Leonenko · Answer 3 · 2016-02-22T12:29:22.307

3

SHA-1 is a hashing algorithm, not an encryption one. It's impossible to 'decrypt'. Read about SHA-1 on wikipedia and keep in mind it is not safe security wise.

edited Feb 22 '16 at 12:29

answered Feb 22 '16 at 12:24

Ivan Leonenko

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How to decrypt sha1 encrypted string C#

3 Answers3