checksummas

Checksummas are an informal plural term used to refer to checksums and related data integrity values used to verify that data has not been corrupted during storage or transmission. The word is a playful extension of "checksum" and is encountered in community discussions, documentation for some projects, and educational materials, rather than as a formal standard term.

Checksummas are produced by applying a checksum algorithm to a data block. They come in two broad categories: non-cryptographic checksums, such as CRC32 and Adler-32, designed to detect common random errors with low computational cost; and cryptographic hashes, such as SHA-256 and SHA-3, that produce fixed-length digests with resistance to deliberate tampering and preimage resistance. In practice, checksummas are often represented as hexadecimal or base64 strings and attached to files, blocks, or messages.

Common uses include error detection in file transfers, software distribution, and archival formats (for example, zip and tar), network protocols, and database replication. In many protocols, a checksum is used to verify integrity after transmission; CRCs are widespread in networks, while cryptographic hashes are favored when authenticity is a concern. Standards and formats that specify checksummas include various RFCs for CRC algorithms and the embedding of hashes in different file formats.

Limitations: a checksum is not a guarantee of data integrity against intentional modification, especially with weaker algorithms. Collisions exist, and an attacker could potentially craft two inputs with the same checksum. Therefore, checksummas are often used in combination with digital signatures or message authentication codes when security is paramount.

Related topics include checksum, hash function, digital signature, MAC, and error detection code.