How to audit password strength for excel workbooks holding sensitive financial data
- Step 1Open the auditor — The Excel password-tester redirects to the Password Entropy Auditor at
/security-tools/password-entropy-auditor. There's no file to upload — you're scoring the password, not the financial workbook. - Step 2Paste the password you plan to use on the financial file — Type or paste into the Password field (placeholder
Type or paste a password). It shows in plain text — fine since nothing leaves your browser, but do it on a private screen, not in an open-plan finance bullpen. - Step 3Click Run Password Auditor — zxcvbn scores it locally. No network call is made, so even a live treasury password is safe to test here.
- Step 4Check the score against the sensitivity of the data — For payroll, P&L, or deal data, require Score 4 · Excellent with a crack time of centuries. A
3 Strongthat cracks in a day is not acceptable for material financial information. - Step 5Reject anything with a warning, no matter how long — A
warningsuch asThis is a very common passworddisqualifies the password even if it's lengthy. Finance passwords built from the firm name plus a year reliably trip these warnings — abandon that base entirely. - Step 6Apply the certified password and control its distribution — Once you reach
Score 4 · centuries, set it in Excel via File → Info → Protect Workbook → Encrypt with Password, then share the password through a separate channel from the file itself.
Finance passwords that fail (real zxcvbn results)
Common patterns from finance teams, scored by the auditor. Crack times are the offline fast-hash figures the tool reports — the right model for an exfiltrated workbook.
| Candidate password | Score | Crack time (offline fast hash) | Why it fails |
|---|---|---|---|
Acme2026 | 2 · Fair | less than a second | Company name + fiscal year is the single most predictable finance pattern |
Finance1 | 1 · Weak | less than a second | Word + digit; also flagged with the warning This is a very common password |
Summer2026! | 2 · Fair | less than a second | Looks complex; word + year + symbol is a known pattern, flagged as similar to a common password |
J0hn.Smith | 2 · Fair | less than a second | A CFO's name with l33t substitution — names are in zxcvbn's dictionaries |
xK9#mL2vQp | 3 · Strong | 1 second | Random but too short — 10 characters can't withstand a GPU offline grind |
Password targets by financial data class
A practical certification bar for finance teams. Require the higher tier as the data's sensitivity and regulatory weight increase.
| Data class | Minimum auditor result | Example fit-for-purpose password |
|---|---|---|
| Internal draft figures, non-material | Score 3 · Strong (longer is better) | A 14+ char random string, audited to ≥ hours |
| Departmental P&L, budgets | Score 4 · Excellent, crack time ≥ days | maple-rivet-cobalt-83 (3 words + digits) |
| Payroll, employee comp, PII | Score 4 · Excellent, crack time centuries | glacier-pencil-vivid-7-quartz (4 unique words) |
| M&A, board deck, material non-public info | Score 4 · Excellent, crack time centuries, unique per file | A fresh 5-word passphrase, never reused |
Cookbook
Real auditor output for the passwords finance teams actually choose. Each score and crack time is the genuine zxcvbn result for that exact string.
The classic 'CompanyName + Year' payroll password
It's the default finance reflex: the firm name and the current fiscal year. It passes corporate complexity rules and dies instantly to the auditor, because it's the first thing a targeted attacker tries.
Password: Acme2026 Result: Score 2/4 · Fair Crack time (offline fast hash): less than a second Warning: (none, but the pattern is trivially guessable) → Reject for any file with real numbers in it.
Naming a colleague is worse than it looks
Using a finance lead's name with a couple of digit swaps feels obscure. zxcvbn keeps a names dictionary, so it scores poorly and the crack time is sub-second.
Password: J0hn.Smith Result: Score 2/4 · Fair Crack time (offline fast hash): less than a second Warning: (none) → Names + l33t are weak. Avoid people, companies, and tickers.
Random isn't enough if it's short
A 10-character random password reaches Score 3 but only ~1 second of offline crack time. For an exfiltrated payroll file that's an afternoon of GPU time. Length is the missing ingredient.
Password: xK9#mL2vQp Result: Score 3/4 · Strong Crack time (offline fast hash): 1 second Warning: (none) → Not enough for payroll. Add words or characters.
Certifying a payroll password to centuries
Four unrelated, uncommon words with separators and a digit clears the bar for the most sensitive HR and finance data: Score 4, centuries to crack.
Password: glacier-pencil-vivid-7-quartz Result: Score 4/4 · Excellent Crack time (offline fast hash): centuries Warning: (none) → Certified for payroll. Apply in Excel; share via a separate channel.
Iterating a budget-file password up to grade
Start from the instinctive weak choice, follow the suggestions, and re-run until it clears. The whole loop happens locally in seconds.
Try 1: Q4Budget26 → Score 2/4 · Fair · less than a second
Try 2: Q4-Budget-Maple → Score 3/4 · Strong · 6 hours
Try 3: Q4-Budget-Maple-Rivet-Cobalt
→ Score 4/4 · Excellent · centuries ✓Edge cases and what actually happens
Company name and fiscal year are the weakest possible base
Always rejectedAcme2026, AcmeFY26, Q4-2026 and the like score 1–2 with sub-second crack times. They feel internal and obscure but are exactly the strings a targeted attacker seeds first. No amount of trailing symbols rescues a company-plus-year base — start from unrelated words instead.
The auditor can't recover a financial file you're locked out of
Not supportedzxcvbn estimates attack time; it does not crack anything, and JAD cannot recover a forgotten AES-256 password — that's the point of strong encryption. For a critical financial workbook, store the certified password in a corporate password manager, not in your head alone.
A Score 4 famous phrase is risky for material data
Read the crack timecorrecthorsebatterystaple scores 4 but the auditor still reports only ~8 hours, because zxcvbn knows the phrase. For M&A or board-level data, don't trust the number 4 alone — push for a crack time of centuries using your own uncommon words.
Reusing one password across the whole finance folder
Compliance riskAudit a password and it might score 4 — but if every payroll and P&L file shares it, a single leak compromises them all. Use a unique strong password per sensitive workbook. The tool scores each candidate; your process must enforce uniqueness.
Excel silently accepts the weak password you just flagged
Excel has no meterExcel's Encrypt with Password dialog applies AES-256 to Acme2026 without complaint, producing a file that's cracked in under a second offline. The encryption is strong; the password is the breach. Audit before you commit it to a financial file.
A warning line outranks a high score
Hard failIf zxcvbn returns This is a very common password or This is similar to a commonly used password, the candidate is disqualified for financial use regardless of length. It matched a leaked-password list, which is fatal — finance passwords reusing common bases routinely trip this.
Symbol substitutions don't satisfy real-world strength
Low impactP@yr0ll! and similar l33t transforms are the first thing attack tooling tries, so zxcvbn discounts them — P@ssw0rd itself scores 0. Complexity-rule compliance is not strength; the auditor measures the latter.
The crack time shown assumes a fast offline attack
By designThe report shows zxcvbn's offline_fast_hashing_1e10_per_second figure (10 billion guesses/sec), which is the correct threat model for an exfiltrated financial file an attacker can grind on a GPU. It deliberately ignores the friendlier online-throttled numbers that would over-flatter your password.
Encrypting the file is only half the job
Distribution mattersA centuries-strong password is wasted if you email it alongside the file. Share the file and the password through separate channels (one by email, one by phone/SMS), and treat the password like the sensitive data it protects.
Sheet protection won't secure financial figures
Different threatExcel's Protect Sheet (the edit/read-only lock) uses a weak legacy hash with no encryption and is removed in seconds — auditing that password is meaningless. This tool is for the Encrypt with Password AES-256 password, the only one whose strength actually protects the numbers.
Frequently asked questions
What is a safe minimum password for an Excel file with payroll or P&L data?
Require Score 4 · Excellent with a crack time of centuries — in practice four or more uncommon, unrelated words (roughly 20+ characters), joined with separators. Avoid your company name, fiscal years, quarter labels, and any colleague's name; all of those score 1–2 and crack in under a second.
Is Excel's AES-256 encryption actually secure for financial data?
The cipher is strong: modern .xlsx uses AES-256 with a key derived from your password via a slow PBKDF2/SHA-512 stretch. The encryption is not the weakness — the password is. Strong AES-256 plus a weak password equals an easily cracked file, which is why auditing the password to Score 4 · centuries is the part that matters.
Why does our standard 'CompanyName2026' password score so badly?
Because company-name-plus-year is one of the most predictable patterns there is, and zxcvbn models exactly how attackers exploit it. Acme2026 scores 2 with a sub-second offline crack time. Targeted attackers seed dictionaries with the victim firm's name and recent years, so this base is effectively pre-cracked.
Can I audit a colleague's Excel password without their file?
Yes — the tool scores a password string and never touches a file. You can paste any candidate password and read its score and crack time. It can't read, open, or test an actual .xlsx, and it can't tell you what password a given file uses; it only evaluates the string you type.
How should I store the strong password once it's certified?
In a corporate password manager, not a sticky note or a shared spreadsheet. Strong AES-256 encryption is unrecoverable if the password is lost, so for a critical financial workbook the recovery plan is the password vault entry, not a brute-force tool — JAD can't recover it for you.
Is a passphrase or a random string better for a financial file?
Test both — the auditor often surprises people. A 16-char random string can score 4 yet report only 12 days, while a fresh 4-word passphrase scores 4 with centuries and is far easier to type correctly into Excel. Pick whichever candidate reaches centuries; passphrases usually win on both strength and usability.
Does this audit the file, or just the password?
Just the password. There is no file upload. You audit the candidate string here, then apply the winning password in Excel's Encrypt with Password dialog. To act on the workbook's contents — redacting PII before encryption, for instance — use a dedicated tool like the email and phone scrubber.
What if I need to prove a financial file wasn't altered after I sent it?
Encryption protects confidentiality, not integrity proof. Generate a hash of the file with the SHA-256 fingerprinter and record it; the recipient can re-hash on receipt to confirm the file is byte-identical to what you sent. Pair that with the strong password for both confidentiality and tamper-evidence.
Does the auditor send my password to a server to check it against breach lists?
No. zxcvbn runs entirely in your browser and ships its own internal dictionaries and common-password lists locally. There is no network lookup — nothing is sent anywhere, which is exactly why it's safe to test the live password for a sensitive financial file.
We're regulated (SOX / GDPR). Is a Score 4 password enough on its own?
A Score 4 · centuries password is a strong control but rarely sufficient alone for regulated data. Combine it with unique passwords per file, separate-channel password delivery, removal of hidden sheets and metadata before sharing, and an integrity hash. Run the hidden-sheet destroyer and the application-metadata wiper as part of that workflow.
Why does the crack time look harsh compared to other strength meters?
Because the report shows the offline fast-hash scenario — 10 billion guesses per second — which is the realistic threat for a financial file an attacker has copied. Meters that show online-attack numbers flatter weak passwords by assuming rate limits an offline attacker simply doesn't face.
Does adding the password in Excel weaken or strengthen what I tested?
Neither — Excel applies AES-256 around the exact string you tested, so the password's strength carries through unchanged. The score you saw in the auditor is the effective strength of the file's protection. There's no separate Excel-side strengthening step to rely on.
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