Checksum
A checksum is a value computed from data and used to detect unintended changes or corruption by comparison with a reference value or recomputation.
API Design Patterns
A checksum value is derived data appended to an identifier to help verify that the identifier was received or entered correctly.
- How it is used
- Uses checksums to distinguish mistyped identifiers from valid identifiers that simply reference missing resources.
- How deep it goes
- Explains checksum derivation, character encoding, generation, verification, UUID integration, and database handling, but not collision probabilities in depth.
- Examples
- Demonstrates modulo-37 calculation, Base37 character mapping, generated identifiers, verification, and Base32-encoded UUID v4 values.
- What you can do after
- Diagnose identifier typos by recalculating a checksum and reject values whose supplied character does not match.
Acing the CCNA Exam: Volume 2 Advanced Networking and Security
A checksum is a small value derived mathematically from data to allow detection of changes to that data.
- How it is used
- Supports integrity checking for messages transmitted over wireless LANs.
- How deep it goes
- Explains generation, appending, encryption, recalculation, comparison, and rejection, but does not specify a checksum algorithm.
- Examples
- Uses encrypted wireless messages and a checksum-mismatch discard decision as the concrete example.
- What you can do after
- Evaluate whether a received message was altered by comparing independently calculated and transmitted checksums.
Read how Acing the CCNA Exam: Volume 2 Advanced Networking and Security explains checksum →
Troubleshooting Java, Second Edition
A checksum is a computed value derived from data for detecting changes or transmission and storage errors.
- How it is used
- Verifies data integrity across services, databases, environments, storage, and transmission without transferring full datasets.
- How deep it goes
- Defines fixed-size checksums, contrasts cryptographic hashes, names CRC32 and Adler-32, and explains recomputation and comparison.
- Examples
- Uses a downloadable file with CRC32 A12F3B4C and a hashed InvoiceCreated event.
- What you can do after
- Diagnose likely corruption by recomputing a checksum and comparing it with the stored or transmitted value.
Read how Troubleshooting Java, Second Edition explains checksum →
Rust in Action: Systems programming concepts and techniques
A checksum is a value computed from data and stored or transmitted with it so later recomputation can detect changes or corruption.
- How it is used
- Detects corruption in data stored on disk or transmitted across systems.
- How deep it goes
- Explains the save-and-compare procedure, compares checksum families, and implements parity checking in Rust.
- Examples
- Uses Bitcask record headers, byte streams such as “abc” and “abcd”, and a Rust parity_bit function.
- What you can do after
- Build it from scratch by implementing parity checks and applying saved checksums during record parsing.
Read how Rust in Action: Systems programming concepts and techniques explains checksum →
Go in Action, Second Edition
A cryptographic checksum is a digest computed from data that can reveal whether the data has changed.
- How it is used
- Protects Go dependencies against tampering and version drift during development and builds.
- How deep it goes
- Explains checksum roles, paired records, verification sources, and version-control practice without detailing digest algorithms.
- Examples
- Uses go.sum records for github.com/gorilla/mux and the sum.golang.org verification service.
- What you can do after
- Operate/configure Go dependency verification by committing go.sum and maintaining it with go mod tidy.
Related concepts
- hash valuekind of · A hash value is a deterministic, typically fixed-size value produced by applying a hash function to input data, often for lookup, comparison, identification, or integrity checking.
- frame check sequenceused by · A frame check sequence is an error-detection field in a frame that enables a receiver to detect corruption during transmission.
- unique identifierused by · A unique identifier is a value or name that distinguishes an entity or record from others within a defined scope or namespace.
These guides are generated from the text of Manning books by Manning's knowledge graph and link to the sections they draw on. The full books are available on liveBook and at manning.com.