declare @security_string nvarchar( 128 )
set @security_string = pwdencrypt('wery security info')
select pwdcompare ('wery security info',@security_string)

create table TestCards 
    ( UserName varchar( 128 ), CardNo nvarchar( 128 ) )
go
insert TestCards ( UserName, CardNo )
    values( 'user_a', pwdencrypt( 'a1234567890' ) )
go
insert TestCards ( UserName, CardNo )
    values( 'user_b', pwdencrypt( 'b1234567890' ) )
go
insert TestCards ( UserName, CardNo )
    values( 'user_c', pwdencrypt( 'c1234567890' ) )
go
select * from TestCards
go
select UserName from TestCards where pwdcompare( 'b1234567890', CardNo ) =  1 
go
select UserName from TestCards where pwdcompare( 'a1234567890', CardNo ) =  1 
go