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Python Institute PCES Glossary: Key Terms

Python Institute PCES glossary of secure scripting, input validation, secrets, files, identity, hashing, encryption, and evidence terms.

Use this glossary when PCES-30-0x: Certified Entry-Level Security Specialist with Python terms start to blur together. The goal is practical recognition: what the term means in a Python security scenario and what answer it usually supports.

Core security terms

Term Exam meaning
Confidentiality Keeping data from unauthorized disclosure.
Integrity Protecting data from unauthorized or accidental change.
Availability Keeping systems and data usable when needed.
Authentication Proving identity.
Authorization Deciding what an authenticated identity may do.
Least privilege Giving only the access required for the task.
Input validation Checking type, format, range, length, and allowed values before use.
Path traversal File-path manipulation that escapes an intended directory boundary.
Secret A credential or key that grants access and must be protected.
Redaction Removing or masking sensitive values from output, logs, reports, or errors.
Hashing One-way digest used for integrity checks or password verification patterns.
Encryption Reversible protection of confidentiality when the right key is available.
Audit log Evidence record of actor, action, target, time, and result.
Safe failure Failing without granting access, corrupting data, or exposing internals.

Confusion pairs

Pair How to separate them
Authentication vs authorization Authentication proves who; authorization decides allowed action.
Hashing vs encryption Hashing is one-way verification; encryption is reversible confidentiality protection.
Validation vs sanitization Validation decides if input is acceptable; sanitization transforms or cleans input for a context.
Logging vs leaking Logging preserves useful evidence; leaking exposes sensitive values.
Secret vs configuration A secret grants access; configuration changes behavior. Protect secrets more strictly.
Exception handling vs hiding errors Handling expected errors is useful; swallowing all errors removes evidence and may make the script unsafe.

How to study terms

Do not memorize definitions alone. For each term, write one scenario where it is the best answer, one scenario where it is a distractor, and one signal that proves a weaker security choice was made.

Revised on Monday, June 15, 2026