Runs entirely in your browser.

No network calls.
Works offline after load.
Fully auditable.

Your passphrase is the lock.

4-digit PIN: 10,000 combinations.
4 BIP39 words: about 17.6 trillion.
At 1 million guesses per second, full search is about 204 days.

Restore works if the protected headers still exist.

Extra columns are fine.
Missing protected columns are skipped.
Renamed protected headers will not restore.

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Peripamo Masking Tool

All data and computation happens in this browser only.

Step 1

Select Mode

Step 2

Upload Files

No CSV loaded yet.
Step 3

Preview & Select

Step 4

Passphrase

Suggested Strong Passphrase
Step 5

Process & Download

Load a CSV to begin.
How It Works

Show the masking flow before users commit to processing.

The tool swaps selected CSV values for readable tokens, stores the original values in an encrypted mapping file, and restores them later only when the same headers, mapping file, and passphrase are supplied.

1. Select Choose only the columns that contain sensitive values.
2. Mask Replace repeated values with stable, readable word tokens.
3. Restore Recover originals locally with the mapping file and passphrase.
Example Wizard

Pick the sensitive columns.

Users keep operational columns visible and mark only the fields that should be masked before export.

Name Email Order
[x] Sarah Lim [x] [email protected] [ ] INV-2048
[x] Amir Tan [x] [email protected] [ ] INV-2049

Before and after are easy to explain.

The protected CSV stays readable for downstream work, while the real values move into a separate encrypted mapping file.

Before
Name: Sarah Lim Email: [email protected] Order: INV-2048
After
Name: Name_abandon Email: Email_ability Order: INV-2048

Restore only with the right keys.

The original values come back only when the processed CSV, encrypted mapping file, and matching passphrase are used together.

Protected CSV
Name_abandon Email_ability INV-2048
Encrypted Mapping
map:v1:aes-gcm:eyJzIjoi... passphrase: harvest orbit...
Use on a trusted device. The CSV carries only tokens. The encrypted mapping file carries the real values. Restoring requires both the file and the same passphrase.