encryption decryption

Mayur Gujrathi

dear all i am encrypting my password like this
but dont know how to decrypt

Function HashPassword(ByVal password As String) As String
        Dim hashedPassword As String
        Dim hashProvider As SHA256Managed

        Try
            Dim passwordBytes() As Byte
            Dim hashBytes() As Byte
            passwordBytes = System.Text.Encoding.Unicode.GetBytes(password)
            hashProvider = New SHA256Managed
            hashProvider.Initialize()
            passwordBytes = hashProvider.ComputeHash(passwordBytes)
            hashedPassword = Convert.ToBase64String(passwordBytes)


        Finally
            If Not hashProvider Is Nothing Then
                hashProvider.Clear()
                hashProvider = Nothing
            End If
        End Try

8 Replies

Know the answer? Post it — somebody with the same question will find it here.

15y ago
Accepted answer
While doing the encryption there are one way and two way algorithms.

SHA256 is one way algorithm and you can't decrypt it.

Now you want to compare the password with hashed values correct .

http://www.vbdotnetheaven.com/UploadFile/f5b919/7459/
Mayur Gujrathi15y ago
Thanks Murali sir
for giving valuable information
Mayur Gujrathi15y ago
Problem is that i got lot of solutions but algorithm what i have used is very old and lot of passwords are already encrypted through that but now i cant change that code i want code in comparative of my code which decrypts my passwords
which i am not getting
Mayur Gujrathi15y ago
Dear Murali sir
i did not get what you told
simply i want to say i am passing password HO and i am gettin
Tut9HyBycNwiwp/WSN5KPmG5cREufSrUsK6fQSvJ+I4=

now i want to decrypt it
15y ago
Did you decrypt the SHA256 encrypted value?
Mayur Gujrathi15y ago
hello experts i found some code but it is decrypted as sqare box
means if my password is of 2 words then 2 sqare box are coming as decrypted result

Public Function Crypt(ByVal inp As String, ByVal Key As String) As String
        ' encryption based on the ryndael algorithem
        Dim Sbox(0 To 255) As Long
        Dim Sbox2(0 To 255) As Long
        Dim j As Long, i As Long, t As Double
        Dim K As Long, temp As Long, Outp As String

        For i = 0 To 255 'Create SBox #1
            Sbox(i) = i 'and fill with
        Next i 'successive values

        j = 1
        For i = 0 To 255 'Create SBox #2
            If j > Len(Key) Then j = 1 'And fill with key
            Sbox2(i) = Asc(Mid(Key, j, 1)) 'data, repeatedly
            j = j + 1 'until the SBox is
        Next i 'full

        j = 0 'Initialize j
        For i = 0 To 255 'Scramble SBox #1
            j = (j + Sbox(i) + Sbox2(i)) Mod 256 'with data from
            temp = Sbox(i) 'SBox #2
            Sbox(i) = Sbox(j)
            Sbox(j) = temp
        Next

        i = 0 'Initialize i
        j = 0 'Initialize j

        For x = 1 To Len(inp) 'Process the data passed on to us
            i = (i + 1) Mod 256 'Increment i
            j = (j + Sbox(i)) Mod 256 'Increment j
            temp = Sbox(i) 'Scramble SBox #1
            Sbox(i) = Sbox(j) 'further so that the encryptor
            Sbox(j) = temp 'will never repeat itself
            t = (Sbox(i) + Sbox(j)) Mod 256 'Get ready to create "random" byte
            K = Sbox(t) 'Get "random" byte

            Outp = Outp + Chr(Asc(Mid(inp, x, 1)) Xor K) 'Xor the data with the "random" byte
        Next x
        Crypt = Outp 'Return the Output Data
    End Function
Vulpes15y ago
If you do want symmetric rather than one-way encryption, then I'd suggest AES.

Check out the example in MSDN (http://msdn.microsoft.com/en-us/library/system.security.cryptography.aescryptoserviceprovider.aspx).
15y ago
SHA256 is one way algorithm so you can't decrypt it.