Purpose

MHM Rentiva uses a multi-layer security architecture (Defense-in-Depth) to protect vendors' financial data and personal information. This page explains encryption methods, data isolation, and audit trail mechanisms.

🛡️ Security & Privacy Layers

Vendor data is protected by four main layers, from the database level to the application interface.

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🔒 1. Financial Data Encryption (IBAN Security)

Vendors' IBAN data is never stored as plain text in the database.

AES-256-CBC Encryption

• Algorithm: Industry-standard AES-256-CBC.
• Key Management: Keys derived from WordPress AUTH_KEY and SECURE_AUTH_SALT constants.
• Fail-Safe: If the encryption library (OpenSSL) is not available, the system returns an empty value and stops the save to prevent data leakage.

// VendorApplicationManager::encrypt_iban();
// Encrypted data is stored using base64_encode().

Critical Warning

Changing the security keys in wp-config.php renders all existing encrypted IBAN data unreadable. These keys must always be backed up.

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🚦 2. High-Criticality Field Change Approval

Changes to critical fields such as IBAN by the vendor do not take effect immediately — an Admin Approval Process is triggered.

IBAN Change Workflow

1. Request: The vendor enters a new IBAN.
2. Temporary Storage: The new IBAN is encrypted and stored in the _mhm_rentiva_pending_iban meta field.
3. Admin Notification: A counter badge appears in the admin panel.
4. Approve/Reject: If the admin approves, the temporary IBAN is moved to the main IBAN field. If rejected, the temporary data is deleted and the vendor receives an email.

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📁 3. Data & Media Isolation

Vendors cannot access other users' data or media files.

• Media Isolation: The ajax_query_attachments_args filter restricts vendors to seeing only the images they have uploaded.
• Dashboard Isolation: The VendorOwnershipEnforcer class automatically adds a post_author filter to all database queries, preventing unauthorized access.

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📝 4. Audit Trail

All critical security events are logged via AdvancedLogger.

Event	Content	Level
IBAN Change	"Vendor #X requested an IBAN change."	INFO
Login Attempt	Failed vendor dashboard login attempts.	WARNING
Payout Approval	"Admin #Y approved a payout for Vendor #X."	CRITICAL

Logs can be monitored from the System Logs section of the admin panel and are automatically purged based on the mhm_rentiva_log_retention_days setting.

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⚙️ 5. Technical Security Summary

Mechanism	Protection Type	Detail
Nonce (CSRF)	Form Security	Unique token for every AJAX and form operation.
Capability	Authorization	Access outside the rentiva_vendor role is blocked.
Masking	Privacy	Only the last 4 digits of IBANs are shown in the UI.

Section Summary

• IBAN data is stored encrypted with AES-256-CBC.
• Critical changes are subject to admin approval.
• Multi-layer isolation keeps vendor data separated from one another.

Changelog

Date	Version	Note
23.04.2026	4.27.2	English translation added.
19.03.2026	4.21.2	Data encryption, IBAN approval workflow, and media isolation details added.