Dim signer As New XceedEncryptionLib.XceedSigningClass()

signer.License( "your license key" )      

Try
  Dim rsa As New XceedEncryptionLib.XceedRSASigningMethodClass() 

  ' The following call to SetRandomKeyPair would, in the real world,
  ' be replaced by the assignment of a Private Key to the
  ' PrivateKey property.
  Dim seed As Object = Nothing
  rsa.SetRandomKeyPair( 512, seed ) 

  ' Set the signing method type
  signer.SigningMethod = rsa 

  Dim source As Object = "This is the data to sign"
  signer.Sign( source, true ) 

  ' Fetch the signature
  Dim signature As Object = rsa.Signature() 

  ' Verify the signature
  signer.Verify( source, true ) 

Catch except As System.Runtime.InteropServices.COMException
  MessageBox.Show( except.ToString() )
End Try