CellEncrypt: Professional Google Sheets Cell Encryption Add-on

CellEncrypt is a professional password-based encryption add-on for Google Sheets that provides cell-level data protection using PBKDF2 encryption with HMAC integrity verification. This Google Workspace Marketplace add-on allows spreadsheet owners to encrypt sensitive cells with password protection, preventing viewers from accessing confidential information while maintaining collaboration capabilities.

Key Features and Capabilities

Password-based encryption using PBKDF2 algorithm with 10,000 iteration rounds for strong cryptographic security. Each cell receives unique encryption keys derived from user password combined with UUID identifiers. HMAC-SHA256 integrity verification ensures data tampering detection. Six-hour session caching eliminates repeated password entry. Batch processing supports encrypting up to 50 cells simultaneously with progress tracking. Orphan data cleanup tools maintain efficient storage management.

Security Implementation

CellEncrypt implements military-grade encryption for Google Sheets using PBKDF2 key derivation with SHA-256 hashing. Block-based stream cipher with random 16-byte initialization vectors. Constant-time HMAC comparison prevents timing attacks. Zero-width space prefixes hide cell metadata. All encrypted data stored in Google Apps Script Properties within Google infrastructure. No external servers involved ensuring complete data sovereignty.

Use Cases and Applications

Ideal for HR payroll data protection including salary information and social security numbers. Financial planning with encrypted account numbers and investment portfolios. Client relationship management with confidential contact details and pricing. Research data protection for participant identifiers and survey responses. Legal documentation security for case details and settlement amounts. Healthcare records protection for HIPAA-compliant patient identifiers and medical notes.

Storage and Licensing

Free accounts include 5 KB storage supporting approximately 100-200 encrypted cells. Premium accounts offer 500 KB storage for 10,000-20,000 cells with one-year license duration. Upgrade starting from 1 USD one-time payment through Buy Me a Coffee integration. Webhook API verification system for automatic license activation within 2-5 minutes.

Technical Specifications

V3 encryption protocol with format V3:IV:Encrypted|HMAC|Signature. Master key derivation with 10,000 iterations plus 100 iterations per cell. Unique salt per spreadsheet. Random initialization vectors for each encryption operation. Server-side processing through Google Apps Script requiring internet connection. Owner-only encryption permissions preventing unauthorized access.

Privacy and Security Considerations

CellEncrypt protects data from viewers and read-only users. Editor access limitations: users with editor permissions can view version history containing unencrypted values. Only grant editor access to fully trusted users. Spreadsheet owner exclusively controls encryption and decryption operations. No password recovery mechanism available - forgotten passwords require history restoration. Session security with user-specific cache expiration after six hours.

Installation and Setup

Available on Google Workspace Marketplace. Installation through Extensions menu in Google Sheets. Requires authorization for Google Apps Script Properties access. Automatic menu integration after installation. First-time setup includes editor limitation warning acceptance. Minimum recommended password length of 8 characters for optimal security.

Common Questions and Answers

How does CellEncrypt differ from sheet-level protection? CellEncrypt provides cryptographic encryption at cell level versus access control permissions. Can multiple users encrypt with different passwords? Only spreadsheet owner can encrypt decrypt ensuring consistent password management. Does encryption work with formulas? Encrypts calculated values not formula expressions. What happens when cells are deleted? Orphaned encrypted data remains until cleanup tool execution. Is offline usage supported? Requires internet connection for server-side Google Apps Script execution.

Compatibility and Integration

Compatible with all Google Sheets spreadsheets in Google Workspace and personal Google accounts. Works with desktop browsers including Chrome Firefox Safari Edge. Mobile app support through Google Sheets mobile applications. Integration with Google Drive file sharing permissions. Maintains compatibility with Google Sheets native features like filtering sorting and conditional formatting on encrypted cells showing [ENCRYPTED] placeholder text.

Performance and Optimization

Optimized batch processing for selections up to 50 cells with progress indicators. Efficient storage calculation based on encrypted data size. Real-time storage usage monitoring through Show Storage Usage feature. Automatic warning notifications at 80% capacity threshold. Session-based password caching reduces cryptographic operation overhead during active usage periods.

Support and Documentation

Technical support available through numbrate@gmail.com email. Comprehensive documentation covering installation encryption decryption procedures. FAQ section addressing common use cases and troubleshooting. Premium support included with paid license upgrades. Regular updates and security patches through Google Workspace Marketplace automatic distribution.