RE: FCS_COP and FCS_CKM interdependency

["Arnold, James L. Jr." <JAMES.L.ARNOLD.JR@saic.com>]

Now that the topic has been brought up, I believe that the dependencies for
the FCS class of requirements are not correct. 

In particular, dependency on secure security attributes (FMT_MSA.2)
certainly has nothing to do with key destruction (FCS_CKM.4) and it also
isn't necessary for most cryptographic operations (FCS_COP). I am also not
sure that key generation (FCS_CKM.1) should depend on FMT_MSA.2 since the
generated keys aren't necessarily based on the acceptance of "secure
attributes" but rather could be based on random or other pre-existing data. 
Note that the FMT_MSA.2 dependencies of all of the FCS class components
yield a problem in that FMT_MSA.2 is dependent on either an access control
or information flow policy. However, encryption seems valid without either
policy (e.g., encrypting the backing store to prevent scavenging or
encrypting tunnels to prevent disclosure of flows without actually control
the flow of information). It is also not clear why key generation
(FCS_CKM.1) or cryptographic operations (FCS_COP) are dependent on key
destruction (FCS_CKM.4).

I tend to think generally that key generation has no dependencies and
cryptographic operations and key destruction depend only on key generation.
If it is believed that key generation needs some support, then FMT_MSA.2 is
not it; especially since that requirement is problematic in itself since it
doesn't support an assignment to narrow the scope of applicable attributes.
Rather, I think this is a case for a considered management requirement as
opposed to a dependency.

Furthermore, the dependencies in class FCS are generally more extensive and
less obviously related that most of the other CC Part 2-defined
dependencies. For example, other requirements include only direct
dependencies while these requirements appear to include some indirect
dependencies.

The point is that all of the dependencies in the FCS class should be
revisited. They should really be necessary and they should be consistent
with the rest of the dependencies in Part 2.

> -----Original Message-----
> From: cc-cmt@nist.gov [mailto:cc-cmt@nist.gov] On Behalf Of Nir Naaman
> Sent: Tuesday, February 24, 2004 7:46 AM
> To: Multiple recipients of list
> Subject: RE: FCS_COP and FCS_CKM interdependency
> 
> 
> It is.
> Dependencies for FCS_COP.1 are listed in CC Part 2 as:
> 
> Dependencies: [FDP_ITC.1 Import of user data without security attributes
> or FCS_CKM.1 Cryptographic key generation]
> 	          FCS_CKM.4 Cryptographic key destruction
>                       FMT_MSA.2 Secure security attributes
> 
>     Nir
> 
> > -----Original Message-----
> > From: cc-cmt@nist.gov [mailto:cc-cmt@nist.gov] On Behalf Of
> > Magos×'nyi Ö±rp×'d
> > Sent: Tuesday, February 24, 2004 1:29 PM
> > To: Multiple recipients of list
> > Subject: FCS_COP and FCS_CKM interdependency
> >
> >
> >
> > Hi!
> >
> > Isn't FCS_COP dependent on FCS_CKM?
> > How can one use crypto securely without managing the keys?
> >
> > --
> > GNU GPL: csak tiszta forrásból
> >
> >
> >
> >
> 
> 
>