Hashing
Hashing is the process of converting data into a fixed-length value using a mathematical algorithm, primarily to verify integrity rather than conceal information.
“Transformation of a variable length string of characters into a usually shorter fixed-length value or key. Hashed values, or hashes, are commonly used in table or database lookups. Cryptographic hash functions are used to secure data.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Hashing?
Unlike encryption, hashing is designed to produce a unique fingerprint of data that changes significantly when the original input is modified.
One-way process: Original data cannot normally be reconstructed from the hash.
Integrity verification: Matching hashes confirm that data has not changed.
Security use: Passwords are often stored as hashes instead of plain text.
Real World Example
A regulated product team is preparing a release where Hashing appears in reviews, test design conversations, or defect triage rather than as an isolated glossary word.
The risk is that the team treats Hashing as interchangeable with nearby ISTQB terms. That makes test scope blurry and can lead to weak evidence for the release decision.
The tester anchors the discussion in the official definition, asks where the concept appears in the product, and designs examples that show the difference between Hashing and similar ideas.
The page becomes useful in practice because Hashing is connected to a specific testing decision, not memorized as a detached definition.
Practice Questions
Question 1
Which statement BEST describes Hashing in the context of ISTQB terminology?
Question 2
A tester needs to explain Hashing to a non‑technical stakeholder. Which approach is MOST appropriate?
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