Formula protection
Cells still compute.
The formula bar stops talking.
XLS Padlock encrypts the formulas you mark sensitive and replaces them with opaque runtime calls. The compiled EXE feeds Excel the right number for every cell, but the formula bar shows nothing your customer can copy.
Excel's built-in formula hiding relies on a password that free tools recover in seconds.
- 01
Free tools remove Excel's formula-hiding password
Excel can hide formulas behind a password. That password is recovered in seconds with any of dozens of free tools. Once unlocked, your formula is right there in the formula bar.
- 02
Saving As copies your formulas
Anyone who opens your workbook can save it under another name and lift every formula. Sheet protection does not prevent that on its own.
- 03
One screenshot of the formula bar copies your model
DCF, regression, option pricing, simulation, custom optimization. The formula bar is the easiest way to lose months of work to a competitor.
Three steps, no formula visible to the end user.
- 01
Pick the cells or ranges to protect
In the XLS Padlock manager, select which formulas you want to encrypt. Cells you do not select stay as plain Excel formulas.
- 02
Compile the workbook
XLS Padlock replaces each protected formula with a cryptic call like =PLEvalFormD(1, COUNT(...)), or =PLEvalForm(1) when it has no cell dependencies. The original formula is encrypted and stored inside the compiled EXE.
- 03
User runs the EXE
At runtime, the EXE decrypts the formula in memory and feeds the result back to Excel. The cell shows the correct value; the formula bar shows the opaque call.
Before protection
Formula visibleCell D4
Formula bar: = B4 * 0.5 + C4 * 0.3 + RISK_PREMIUM
Value: 2,800.00After protection
EncryptedCell D4
Formula bar: = PLEvalFormD(1, COUNT(B4,C4))
Value: 2,800.00 (same result)
Outside EXE: formula missing, cell breaksThe cell value stays correct; the formula bar shows only an encrypted call.
| What they see | Plain workbook | Compiled EXE |
|---|---|---|
| Cell value | = B4 * 0.5 | 2500 (computed correctly) |
| Formula bar | = B4 * 0.5 | = PLEvalFormD(1, COUNT(B4)) |
| Save As | Carries the formula | Carries an opaque call that only works inside the EXE |
| Excel sheet protection | Compatible | Compatible. Avoid Excel's Hidden attribute on cells that protected formulas depend on. |
What formula protection does and does not cover.
- Formulas you do not select stay visible. Pick the ones that hold the IP.
- Each protected formula must stay under 256 characters and cannot use INDIRECT or call VBA user-defined functions.
- Cell data validation and Conditional Formatting rules are not covered by formula protection.
- Names referenced in protected formulas must resolve in the runtime environment.
You stay in control.
XLS Padlock is a one-time purchase, not a middleman between you and your buyers. Everything the protection depends on stays yours.
Shipping since 2013 from G.D.G. Software. A desktop tool you can build a business on.
- The workbook
- Your .xlsx never leaves your machine. You compile it yourself into a standalone EXE.
- The keys
- You generate, count, and revoke activation keys. No per-copy fee, no royalties on your sales.
- The server
- Activations validate against a PHP server you host and own, not ours.
- The customer
- You sell directly. The buyer relationship and the full revenue stay with you.