On 01/05/2015 05:56 PM, Lou Losee wrote:
> Hopefully all of your started proc user ids are PROTECTED otherwise those 3
> invalid password attempts could cause you big problems.
> 
> Lou
> 
> --
> Artificial Intelligence is no match for Natural Stupidity
>   - Unknown
> 
> On Mon, Jan 5, 2015 at 2:21 PM, Mike Schwab <[email protected]> wrote:
> 
>> On Mon, Jan 5, 2015 at 9:45 AM, Vernooij, CP (ITOPT1) - KLM
>> <[email protected]> wrote:
>>> What is the point in trying to find a valid userid, if the userid will
>> be suspended after trying 3 invalid passwords (in our situation)?
>>>
>>> Kees.
>>>
>> But not if you keep rotating IDs.  It is three in a row for the same ID.
>>
>> --
>> Mike A Schwab, Springfield IL USA
>> Where do Forest Rangers go to get away from it all?
>>
No, it's not three failed attempts in a row from the same source for the
same ID; it's three failed logon attempts (if that is the limit) for the
same ID before the next successful logon authentication for that same
ID, whether the logon attempts are spread over seconds, hours, or days,
and across all possible MVS systems and applications that might be
requesting userid authentication.  If your hack attempt rotates through
all known userids more than three times in the same day on a system
where the average userid is only authenticated one or two times a day,
the odds are you will start revoking some userids during the third pass
(and start potentially being noticed).  For a userid that only has one
legitimate logon per week, three bad attempts spread across a week would
be sufficient to cause a revoke.  At a max of three bad password hack
attempts per ID per day, how many years does that take to have
reasonable odds of hacking any individual userid?  How does installation
rules that force users to change their password every 60 to 90 days
affect the odds of that success, since there is a non-zero probability a
user could change to a password value the hacker had already attempted
and will never try again because he already "knows" it is invalid?


-- 
Joel C. Ewing,    Bentonville, AR       [email protected] 

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