- [Narrator] The principle of separation of duties
protects organizations against
the malicious actions of a single rogue employee.
Organizations implement separation of duties
and two-person control to reduce the risk
that a single individual can perform a harmful action.
The separations of duties principle
says that no single person should possess
two permissions that, in combination,
allow them to perform a sensitive operation.
Instead, those permissions should be separated
and held by two different groups of people.
Account reviews and audits should inspect permissions
to ensure that separation of duties is properly enforced.
Let's look at a couple of examples
of separation of responsibilities.
One of the most common requirements
for separation of duties comes in the world of accounting.
Organizations normally separate the duties
of creating new vendors in their accounting system
and authorizing payments to vendors.
This separation prevents a single employee
in the accounting department from creating
a fake vendor and then issuing payments to that vendor
in an attempt to embezzle funds.
When separation of responsibilities is properly implemented,
no single employee would be able to both create
a fake vendor and issue payments to that vendor.
Instead, carrying out this theft
would require the collusion of two employees
with the required privileges.
In this case, information security professionals
would be responsible for configuring
the access control system
to prevent violations of separations of duties.
IT staff may also be the target
of separation of duties controls.
In the world of software development,
this commonly surfaces as a requirement
that developers may not put their own code into production.
Instead, they must submit code
to a testing and evaluation process,
and only after the code passes rigorous security
and functionality checks does a separate person
move the code into production.
Two-person control, also known as dual control,
is a related principle but works
in a slightly different way.
Instead of separating sensitive actions from each other,
two-person control requires the authorization
of two individuals to carry out a single action.
The most commonly cited example of two-person control
is the process used to launch missiles in the military.
Movies are full of scenes that show the process
that requires two launch officers
to simultaneously turn their command keys
to launch a missile.
This requires that both officers agree
to perform the launch.
The keys are physically separated
by a sufficient distance that one person
cannot turn them both at the same time.
In the accounting world, we often see
two-person control in organizations that require
two different signatures on paper checks
that are above a certain threshold amount.
In the world of IT, information security professionals
often implement two-person control
for especially sensitive actions.
For example, the emergency access procedures
that grant system administrators privileges
that they do not normally possess
may require that two different administrators
authenticate to perform that action.
Separation of duties and two-person control
are designed to limit the likelihood
of fraud and abuse by requiring
the concurrence of two individuals
to perform sensitive actions
and combinations of actions.