Category
Fundamentals
The key ideas: anonymization, pseudonymization, redaction, hidden data, re-identification.
- 6 min readWhich Numbers in a Document Are Most Dangerous If They Leak?A card number, an IBAN and a birth date are not equally dangerous. Here is a harm-based ranking, sourced from official consumer-protection bodies.
- 6 min readTokenization, Hashing or Encryption: Which One Pseudonymizes?The words get mixed up in every guide. This article walks through what a counter, a hash, a keyed hash and encryption actually do to a value, and which one fits a document you plan to share.
- 5 min readWhat Does It Mean to Sanitize a Document?A lawyer redacting a contract and an IT team blocking a macro are both sanitizing something. They are just not solving the same problem.
- 6 min readBarcodes and QR codes on documents: what they reveal, and why to mask themA barcode or QR code often repeats the name, address or account number you just redacted. Here is what common codes contain, and how to check one first.
- 6 min readLetterheads, headers and footers: the details that identify a documentThe body of a letter is not the only place a sender's name hides. Headers, footers and letterheads carry it too, and this guide shows where to look.
- 7 min readOnline PDF Tools: What Happens to the File You Upload?When you upload a PDF to an online tool, a copy leaves your device. Here is what that means, what the GDPR requires, and how to avoid it.
- 6 min readRedaction, Encryption or a Password: Which Protects a Document?A password, encryption and redaction do not protect a document the same way. Here is what each one really stops, and how to combine them for a safe send.
- 6 min readPublic, internal, confidential: how classification decides what to maskMost companies label documents public, internal, confidential or restricted. Here is what each level means, and what to mask before sharing one more widely.
- 6 min readPII vs personal data: what's the difference between US and EU law?Americans say PII. Europeans say personal data. The EU definition is wider, and that changes what you should mask in a document before you send it.
- 6 min readConsistent Pseudonyms: How to Replace Names Without Losing MeaningA black bar erases a name, and the story around it. Here is how to replace names with consistent, readable labels instead, and keep the label list itself safe.
- 7 min readWhy Documents Are Harder to Anonymize Than DatabasesDeleting a column removes a name from every row at once. A letter has no column, so the same name must be found in the greeting, the address and the signature, one by one.
- 6 min readHidden data in your documents: metadata, comments and tracked changesA clean-looking file can still name its author, keep a deleted clause or reveal where a photo was taken. Here is where hidden data lives and how to remove it.
- 6 min readWhy blacking out text in a PDF often failsA black rectangle covers text but does not remove it. Here is how hidden words come back, what real redaction does, and how to test your own file.
- 6 min readAnonymization, pseudonymization, redaction: what is the difference?Anonymous data leaves the GDPR. Pseudonymized data stays in it, at least for whoever holds the key. Redaction is what you do to the page. Here is how to tell them apart.
- 6 min readRe-identification: why removing names is not enoughTake the name out of a document and the person is often still there. What gives people away, and a checklist by reader: the public, a colleague, an AI tool.
- 5 min readWhat counts as personal data in a document? A line-by-line guideA name is personal data. So is an employee number, a rare job title or a sick-leave date. Here is how to read a contract, a report or a letter line by line.
- 6 min readWhat is document redaction? Definition, uses and limitsRedaction removes information from a copy of a document for good. Here is what the word means, when the law expects it, a six-step method, and its limits.