unwrap

Unwrap is a verb with several related meanings across everyday use, technology, and mathematics. In general language, to unwrap means to remove wrapping, packaging, or a protective covering from an object in order to reveal its contents. This sense is common in shopping, gifting, food preparation, and parcel handling, and it can be used figuratively to describe revealing what is inside something concealed.

In cryptography and information security, unwrap denotes the inverse operation of wrap. A wrapped (or encrypted) key is recovered by unwrapping it with a key-encrypting key (KEK) to obtain the original key material. This concept is part of key management and is standardized in algorithms such as the AES Key Wrap scheme. Unwrapping is typically designed to ensure the integrity and confidentiality of the recovered key material.

In programming, unwrap is used to describe extracting a value from a container that may or may not hold one. Languages feature construct- or method-names such as unwrap to obtain the contained value or to raise an error if no value is present. For example, in some languages an optional or result type provides unwrap to access the successful value, with failure triggering an exception or panic.

In signal processing and related fields, phase unwrapping refers to transforming a wrapped phase angle, which is limited to a principal interval (such as −π to π), into a continuous phase representation by removing discontinuities. This is important in applications like interferometry, spectroscopy, and radar.

In computer graphics, UV unwrapping is the process of projecting a 3D model’s surface onto a 2D plane to create texture coordinates for mapping images onto the model.