Signature
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TLDR: A signature in computing is a data marker used to verify the integrity, authenticity, or identity of digital content, systems, or processes. It ensures that data has not been tampered with and is recognized by the system or application. Common types of signatures include cryptographic signatures for security, filesystem signatures for disk partitioning, and method signatures in programming languages to define function behavior.
https://en.wikipedia.org/wiki/Digital_signature
In partitioning, a signature like the one in the MBR (Master Boot Record) is a two-byte identifier (0x55AA) at the end of the first 512 bytes of a storage device. This signature validates the MBR as a bootable record recognized by the system firmware. Similarly, filesystems often include unique signatures to identify the disk format, ensuring compatibility during disk mounting and disk access operations.
https://www.kernel.org/doc/html/latest/filesystems/index.html
In security, cryptographic signatures ensure the authenticity of data or software. These signatures, generated using asymmetric encryption algorithms like RSA or ECDSA, verify that the content originates from a trusted source and has not been altered. For example, signed firmware or signed kernels rely on these signatures to pass checks like Secure Boot, protecting systems from unauthorized modifications. By ensuring authenticity and integrity, signatures play a vital role across computing disciplines.
https://www.nist.gov/itl/special-publications/nist-special-publication-800-107
Signature