Disinvocability

Disinvocability is a concept in computer security and software design that describes the extent to which a system can prevent the invocation of particular functions, APIs, or services. It is the counterpart to invocability, which denotes the ability to invoke.

Definition and scope: Disinvocability encompasses mechanisms that block, deny, or regulate calls at various boundaries such as user, process, network, or container. It can be enforced at design time through access control models, licensing, or feature flags, and at run time through authorization checks, authentication, request filtering, sandboxing, and code signing.

Applications: It is especially relevant for security-sensitive operations (privileged APIs, payment processing, administrative tools) where preventing unauthorized invocations reduces risk. It also appears in platforms with phased exposure of features, where feature flags or kill switches can disable functionality during incidents or deprecation.

Methods: Common techniques include authentication and authorization, capability-based security, input validation, rate limiting, request filtering, sandboxing, and policy engines. Code signing and tamper-evident deployment support disinvocability by ensuring only trusted components run. Kill switches and feature flags provide operational control to instantly disable functionality.

Trade-offs and limitations: Disinvocability adds protection but can introduce complexity, performance costs, and the risk of misconfiguration. It may not be absolute against a fully compromised system or side-channel attacks; auditing and defense-in-depth are required.

See also: invocability, access control, capability, sandbox, kill switch, feature flag, security governance.