Is there a method to get plain-text from cipher-text in HMAC SHA-1, given that the key is known?

This is technically not even an attack. We have all the resources at hand, except for the original plain-text. We have the cipher-text (to be converted back to plain-text), as well as the key.

The cipher-text stored in the DB is as follows :

HKnvB41kkow+KkR4c7G/8vusmEM=

The hashing function used is as follows:

Public Shared Function EncryptPasswordInHash(ByVal password As String) As String Dim EncodedPassword As String = password Dim Hash As New HMACSHA1() Hash.Key = StrToByte(LicensingBLL.ENCRYPTION_KEY) EncodedPassword = Convert.ToBase64String(Hash.ComputeHash(Encoding.Unicode.GetBytes(password))) Return EncodedPassword End Function

The key we have used is : "zooooooooooo123"

Is there any possible way to retrieve the plaintext with all the given information? Any help would be greatly appreciated. Thanks, in advance.