Blind Rename Files¶

Obfuscate filenames for unbiased analysis: macOS App & Bash Scripts

A macOS app and Bash scripts to blind-rename files in a folder for unbiased analysis. Original filenames are saved in a dictionary so they can be restored at any time.

What it does¶

Each file in a folder is renamed to a 20-character uppercase hash derived from its original filename. A name_dictionary.csv mapping is saved alongside the files. Running the revert restores all original names and archives the dictionary.

Files created in the folder:

Subfolders are never touched.

How it works¶

flowchart TD
    A[Select folder] --> B{Run as root?}
    B -- yes --> X[Abort]
    B -- no --> C{name_dictionary.csv or<br/>Analysis_file.csv exists?}
    C -- yes --> X1[Abort: already renamed]
    C -- no --> D{name_dictionary_DEPRECATED.csv<br/>exists?}
    D -- yes --> X2[Abort: already randomized once<br/>delete DEPRECATED file]
    D -- no --> E{200 or more files?}
    E -- "yes, user answers N" --> X3[Exit, no changes]
    E -- "no, or user answers Y" --> F[Next file in folder<br/>top level only, subfolders skipped]
    F --> G{name_dictionary.csv, Analysis_file.csv,<br/>.DS_Store or Thumbs.db?}
    G -- yes --> F
    G -- no --> H[SHA hash of filename<br/>uppercase, first 20 alphanumeric chars]
    H --> I[Keep original extension]
    I --> J[Rename file]
    J --> K[Append Old,New to name_dictionary.csv<br/>append New to Analysis_file.csv]
    K -- more files --> F
    K -- all files done --> L[Blind analysis using Analysis_file.csv]
    L --> M[Revert: read name_dictionary.csv]
    M --> N[Restore original names]
    N --> O[Rename dictionary to<br/>name_dictionary_DEPRECATED.csv]

macOS App¶

Download BashBlindRename.app from the releases page.

1. Open the app.
2. Drag and drop your folder onto the drop zone.
3. Click Blind Rename to obfuscate filenames.
4. Click Revert Rename to restore original names.

Bash Scripts¶

Requirements¶

• Bash (macOS or Linux)
• shasum, pre-installed on macOS and most Linux systems

Setup¶

chmod +x bash_blind_rename.sh revert_rename.sh

Blind rename a folder¶

./bash_blind_rename.sh path/to/folder

Revert to original names¶

./revert_rename.sh path/to/folder

Example¶

Starting folder:

temp/
  foo_1.txt
  foo_2.txt
  foo_3.txt
  subfolder/
    bar_1.txt

After ./bash_blind_rename.sh temp/:

temp/
  007937B3F4F4D9F58B7D.txt
  3C27A89C60DE090DE1F6.txt
  760A83AE04023DD099FC.txt
  name_dictionary.csv
  Analysis_file.csv
  subfolder/
    bar_1.txt

subfolder/ and its contents are untouched.

name_dictionary.csv:

Oldname,Newname
foo_1.txt,007937B3F4F4D9F58B7D.txt
foo_2.txt,3C27A89C60DE090DE1F6.txt
foo_3.txt,760A83AE04023DD099FC.txt

After ./revert_rename.sh temp/:

temp/
  foo_1.txt
  foo_2.txt
  foo_3.txt
  name_dictionary_DEPRECATED.csv
  subfolder/
    bar_1.txt

Safety rules¶

License¶

See LICENSE.