Information Security Policy - How Detailed Should it Be?

Quite often I see information security policies writtenOn the other hand, detailed policies should be
in too much detail, trying to cover everything fromintended for operational use, and focused on a
strategic objectives to how many numerical digits anarrower field of security activities. Examples of such
password should contain. The only problem with suchpolicies are: Classification policy, Policy on acceptable
policies is that they contain 50 or more pages, and -use of information assets, Backup policy, Access
no one is really taking them seriously. They usuallycontrol policy, Password policy, Clear desk and clear
end up serving as artificial documents whose solescreen policy, Policy on use of network services,
purpose is to satisfy the auditor.Policy for mobile computing, Policy on the use of
But why are such policies extremely difficult tocryptographic controls, etc. Note: ISO 27001 does not
implement? Because they are too ambitious - theyrequire all these policies to be implemented and/or
try to cover too many issues, and are intended for adocumented, because the decision whether such
wide circle of people.controls are applicable, and to what extent, depends
This is why ISO 27001, the leading informationon the results of risk assessment.
security standard, defines different levels ofBecause such policies should prescribe more details,
information security policies:they are usually longer - up to ten pages. If they
- High-level policies, such as the Information Securitywere much longer than that, it would be very difficult
Management System Policy - such high level policiesto implement and maintain them.
usually define strategic intention, objectives etc.In other words, information security is too complex
- Detailed policies - this kind of policy usually describesan issue to be defined in a single policy - for different
a selected area of information security in more detail,aspects of ISMS and different "target groups" there
with precise responsibilities, etc.should be different policies. Middle-sized organizations
ISO 27001 requires that Information Securityusually build up to fifteen policies for their ISMS.
Management System (ISMS) Policy, as theOne could argue that this number of policies is
highest-ranking document contains the following: thenothing but overhead for a company. I would
framework for setting objectives, taking into accountcertainly agree if such policies are written only with
various requirements and obligations, aligns with thethe certification audit in mind - such policies will bring
organization's strategic risk management context, andnothing but more bureaucracy. However, if a policy is
establishes risk evaluation criteria. Such a policy shouldwritten with the intention of decreasing the risks,
be actually very short (maybe one or two pages)then it will most probably show its value - if not right
because it's main purpose is for top management toaway, then probably in two or three years, by
be able to control their ISMS.decreasing the number of incidents.