post-quantum · zero-knowledge

One encrypted core for your entire business.

LetterSheets runs HR, accounting, inventory, sales, and procurement on a single double-entry ledger — with every sensitive figure encrypted in your browser.

Get started free Explore modules
general_journal.db
EntryDebitCredit
Cash — Invoice #104212,400—
Sales revenue—12,400
Payroll — July96,200—
Totals108,600108,600
balanced
modules
7
modules on one shared ledger — everything reconciles automatically.
HRAccountingInventoryAssetsSalesProcurementTicketing

Quantum-safe

ML-KEM-768
ML-DSA-65

Zero-knowledge

Keys stay on your device. The server stores only ciphertext.

one platform

Seven modules, one balance.

Each module posts into the same double-entry core, so operations and financials never drift apart.

100

Human Resource

Encrypted records, attendance, leave, benefits, and payroll.
200

Accounting

The double-entry core — payables, receivables, and reports.
300

Inventory

Multi-warehouse stock and movements, valued to the GL.
400

Fixed Assets

Registers, depreciation methods, and disposal.
500

Sales & Orders

Quote to cash, fulfilment to revenue, order returns.
600

Procurement

Requisition to pay, with 3-way matching.
See all seven modules in detail →
security first

Private by architecture, not by policy.

Sensitive fields are encrypted in your browser before they ever reach the server — which only ever stores ciphertext it can't read.

  • Zero-knowledgeYour keys never leave your device.
  • Post-quantumML-KEM-768 key exchange & ML-DSA-65 signatures.
  • Your recovery keyNo silent backdoor, no vendor master key.
Read the security overview →
// what the server stores
employee.salary = "a3F9…c71b"
invoice.amount  = "9dE2…04af"
encryption    = ML-KEM-768
readable      = false
// keys held only by you

Run everything on one encrypted core.

Bring HR, accounting, inventory, and the rest onto a single private platform.

Get started free See pricing