Password Management

 

Password Mana Management gement

 

Password Management  •

Password Protection:  The front line of defense against intruders is the password system. Virtually all multiuser systems require that a user provide not only a name or identier (ID) ut serves also to a authenti!ate password. The password the ID of the individual logging on to the system. In turn" the ID provides se!urity in the following ways#

 

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 The ID determines whether the user is authori$ed to gain a!!ess to a system.

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 The ID determines the privileges a!!orded to the user.

 

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The Vulnerability of Passwords: let us !onsider a s!heme that is widely used on %&I'# a!h user sele!ts a password up to eight  –

!hara!ters.  This is !onverted into a *+it value (,ey input to an en!ryption en !ryption routine).  The en!ryption routine is ased on D-.  The D- algorithm is modied using a

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/+it.  This value is related to the time at whi!h

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 The modied modi ed D- algorithm iis s e0er!ised e0er!ised with a data input !onsisting of a *1+it lo!, of $eros.  The output of the algorithm then serves as input for a se!ond en!ryption.  This pro!ess is repeated for a total of / en!ryptions.  The resulting *1+it output is then translated into an +!hara!ter sequen!e.  The hashed password is then stored" together with a plainte0t !opy of the salt" in the password le

 

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The salt serves three purposes: It prevents dupli!ate passwords  –

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from eing visile in the password le. It e2e!tively in!reases the length of the password without requiring the user to rememer additional !hara!ters.

 

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Access Control: 3ne way to thwart a password atta!, is to deny the opponent a!!ess to the password le. If the en!rypted password portion of the le is a!!essile only y a privileged user" itthen the opponent !annot read without already ,nowing the password of a privileged privile ged user user..

 

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Password Selection Strategies: Password  The goal is to eliminate guessale passwords while allowing the user to sele!t a password that is memorale. 4our asi! tte!hniques e!hniques are in use#  –

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%ser edu!ation. 5omputer+generated passwords. 6ea!tive password !he!,ing.

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Proa!tive password !he!,ing.

 

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User education %sers !an e told the importan!e of using hard+to+guess passwords and !an e provided with guidelines for sele!ting strong passwords. Computergenerated passwords  –

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passwords are quite random in nature !eactive password chec"ing the system periodi!ally runs its own password !ra!,er to nd guessale  –

passwords. The system !an!els any passwords that are guessed

 

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Proactive password chec"ing user is allowed to sele!t his or her own password. 7owever" at the time of sele!tion" the system !he!,s to see if the password is allowale and" if not" re8e!ts it.  –

 The tri!, with a proa!tive password !he!,er is to stri,e a alan!e etween

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user a!!eptaility and stre strength. ngth.

 

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Proactive password chec"ing approaches: 6ule enfor!ement#  –

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9ll passwords must e at least eight !hara!ters long.  The passwords must in!lude at least one ea!h of upper!ase" lower!ase" numeri! digits" and pun!tuation mar,s.

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9nother possile pro!edure is simply to !ompile a large di!tionary of possile :ad: passwords.

 

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Proactive password chec"er techni#ues Mar,ov model# generation of guessale passwords" this model shows a language !onsisting of an alphaet of three !hara!ters. The state of the system at  –

any time is the identity of the most re!ent letter. The value on the transition from one state to another represents the proaility that one letter follows another. Thus" the proaility that the

ne0t letter is " given that the !urrent

 

$ow to Choose a secure password% •

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Do &3T use words or phrases that have personal signi!an!e. Mi0 letters" numers and symols" and use !ase sensitivity  Try to memori$e the password" and avoid writing it  Try down Do not use the same password for everything

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%se a password manager (PM). your It is passwords a utility that !reates an en!rypted le where are stored.  Try  T ry to use :nonsense words.: Do not tell anyody your password.