Need help getting encoding function to work

OK, I have two functions in SQL.   Once function encodes text into a binary data type and the other decodes the data.   This all seems to work great except for when the text has an "R" on the end.   Here is the code for both functions.

CREATE FUNCTION [dbo].[DecryptHN] (@InputString  varchar(11))  
RETURNS varchar (12)
 AS  
BEGIN

declare @ctr tinyint
declare @master varchar(32)
declare @TempKey varchar(255)
declare @Result varchar(32)
declare @FinalResult varchar(12)
declare @Tchar int
declare @Mchar int
declare @strlen int


select @strlen =  LEN(RTRIM(@InputString))

set @TempKey = 'cktm091795.'

set @ctr = 1
set @Result = ''

WHILE @ctr <= @strlen
   BEGIN
   set @Mchar = ASCII(SUBSTRING(@InputString, @ctr, 1))
   set @Tchar = ASCII(SUBSTRING(@TempKey, @ctr, 1))
   set @Result = @Result + cast(char(@Mchar ^ @Tchar)as varchar(32))
   SELECT @ctr = @ctr + 1
   if @ctr > @strlen
     BREAK
 
   END
   Set @FinalResult=LEFT(@Result,3)+'-'+RTRIM(SUBSTRING(@Result,4,7))+SUBSTRING(@Result,11,1)
Return (@FinalResult)

END

and the other function.


CREATE FUNCTION [dbo].[EncryptFullHN] (@InputString  char(11))  
RETURNS binary (11)
 
BEGIN

declare @ctr tinyint
declare @master varchar(32)
declare @TempKey varchar(255)
declare @Result varchar(32)
declare @Tchar int
declare @Mchar int
declare @BinResult binary(11)

set @TempKey = 'cktm091795.'

set @ctr = 1
set @Result = ''
WHILE @ctr <= datalength(@InputString)
   BEGIN
     set @Mchar = ASCII(SUBSTRING(@InputString, @ctr, 1))
     set @Tchar = ASCII(SUBSTRING(@TempKey, @ctr, 1))
     set @Result = @Result + cast(char(@Mchar ^ @Tchar)as varchar(32))
     SET @ctr = @ctr + 1
END

set @BinResult = CAST (@Result AS binary(11) )

Return (@BinResult)


END


To test this you can run this SQL.

select dbo.encryptfullhn('11602105R')

it should return 0x525A425D0208010219157C
but it returns    0x525A425D020801026B150E

What am I missing here?