Tired of stock dialers that gather your calling statistics and send your personal contacts list to remote cloud servers? Secure Dialer processes absolutely everything locally. Zero internet permissions mean zero tracking, zero ads, and zero data leaks. Guaranteed.
Most dialers monetize your communication patterns and upload your address book. We believe privacy isn't a premium configuration setting—it must be the foundation of the architecture.
Absence of Internet Permission
Secure Dialer physically excludes the Android INTERNET permission in its manifest. It has no physical way to connect to a server, retrieve tracking code, or upload metadata.
AES-256 SQLCipher Database
Settings, private call logs, custom templates, and speed dials are encrypted inside a local Room SQLCipher database. The database key is secured natively within the device's hardware-backed Android Keystore enclave.
100% Auditable Open Source
No closed binary blobs or obfuscated background modules. Our entire codebase is licensed under the GPLv3, open for public audits, and compiles cleanly in secondary sandboxed environments like GrapheneOS.
Interface Showcase
Elegantly Responsive Design
Designed purely with Jetpack Compose following modern Material 3 guidelines. Enjoy custom shapes, dynamic typography, adaptive grid alignments, and absolute clarity.
SCREEN EXPLORATION
Tactile Smart Dialpad
Your primary hub for quick dialing, speed dials, and smart local directory matching. Real tactile response paired with hardware privacy guarantees.
Smart T9 Contact Search
Type numbers corresponding to names to search instantly. Highly responsive local algorithm matches contacts without remote database lookups.
Tactile Haptics & DTMF
Provides satisfying feedback vibration with real DTMF tone generation for easy navigation of corporate automated menu directories.
Speed Dial Indices
Assign keys 1 through 9 to trigger immediate calls to your most important contacts without navigating deep directories.
Utility Integration
Features Packed Into A FOSS Footprint
Designed with high functionality to replace all features of stock dialers while incorporating offline-first security utilities.
Offline Spam Blocklist
Silences telemarketers and fraud numbers using Android's native CallScreeningService. Blocklists are checked, imported via CSV, and managed completely offline.
🎭 Fake Call Simulator
Set custom delayed multi-call sequences that trigger a high-fidelity incoming caller UI screen. Answering simulates an active call with timer counters and dialpads to help escape awkward meetings.
Call Recording & Notes
Record conversations or write persistent encrypted notes directly inside the active call window. Audio is stored in the application's secure isolated local database sandboxed sandbox.
⏰ Callback Reminders
Decline an incoming call with text but forget to callback? Use callback reminders from call detail screens to establish delayed alerts containing immediate direct call-back actions.
Offline Calling Analytics
Understand your dial patterns over days, weeks, or months. Displays structured duration trackers, missed counts, and top callers via clean native Compose charts that run entirely locally.
Dual-SIM & Speed Dial
Supports seamless SIM selection prompts on active dial triggers, or configure standard primary outbound lines. T9 speed dial maps indices `1` to `9` to dial key numbers immediately.
Permission Transparency
Standard System Permissions Explained Honestly
A dialer app requires permissions to perform system calls. We explain exactly what we request, why we need it, and how your data remains completely insulated.
READ_CONTACTS
Populate Address Book
Why: To look up names, display avatars, and allow search. Security Guarantee: Read completely in local process memory. Never synchronized or written to outside services.
WRITE_CONTACTS
Create & Edit Contacts
Why: Allows adding names, numbers, emails, and notes to your storage directly inside the dialer. Security Guarantee: Operates only via on-device system contacts provider.
CALL_PHONE
Trigger System Calls
Why: Placed in call triggers when clicking numbers or tapping dial icons. Security Guarantee: Only sends commands directly to Android's Telecom subsystem.
READ_CALL_LOG
Display Recent Entries
Why: Populates the "Recents" list, detailing missed, received, or dialed connections. Security Guarantee: Local read. No background scrapers or reporting routines.
SEND_SMS
Send SMS Templates
Why: Sends standard decline templates (e.g., "Sorry, I am driving") directly on call rejection. Security Guarantee: Initiates purely when manually confirmed by you during an inbound call.
RECORD_AUDIO
Active Recording Storage
Why: Allows voice tracking during calls if you tap the Record button. Security Guarantee: Isolated local sandboxed storage. No background passive ear-dropping or wiretaps.
Developer Setup
Independent Source Compilation
Build your own secure, signed APK using standard open source tools. Ensure absolute integrity.
bash terminal
# 1. Clone the repository
git clone https://github.com/Secure-Phone-apps/Secure-Dialer.git
cd Secure-Dialer
# 2. Verify dependencies and run tests
./gradlew testDebugUnitTest
# 3. Assemble release APK signed under your environment keys
./gradlew assembleDebug
# 4. Binary targets can be found under build directory:app/build/outputs/apk/debug/app-debug.apk
Questions & Answers
Frequently Asked Questions
Everything you need to know about Secure Dialer's privacy controls, storage, and build setup.
No. Secure Dialer operates 100% offline. It contains absolutely zero network access declarations (the android.permission.INTERNET permission is not even listed in its AndroidManifest.xml). Your contact list, call metrics, and dialer preferences reside physical on your device, completely sandboxed from any remote servers.
Yes! Your local database is fully encrypted using **SQLCipher** and a dynamically generated **AES-256 database master key** via DatabaseKeyManager. This master key is generated with cryptographically strong SecureRandom and protected using hardware-backed Android KeyStore (using AES in GCM mode with no padding). Even on rooted devices, your private dialer database is safeguarded against unauthorized extractions.
Yes. Secure Dialer is fully compliant with modern Android requirements to act as your **Default Phone Handler**. It implements a custom native InCallService (via MyInCallService.kt) and CallManager to fully display incoming/outgoing calling overlays, control speakers, toggle microphones, and process dialing signals locally.
Secure Dialer offers an innovative dual-tier contact model:
System Contacts: Syncs directly with your Android OS standard contact book (requires standard permissions).
Local-First Contacts: Stored solely inside our app's encrypted SQLite sandbox. They are completely separated from Android's system contact pool. This guarantees that other applications on your device—even those with full system contact permissions—cannot read or harvest these private entries.
Yes! The Dialpad supports classical T9 predictive keypad search. As you tap digit keys on the keypad, the app's internal repository (DialerRepositorySystemSync.kt) instantly maps characters into matching keypad numbers (e.g. tapping "564" resolves to "JOH", showing matching names immediately) to find contacts in fractions of a millisecond.
Instead of relying on heavy cloud push servers that track when you return calls, Secure Dialer leverages standard on-device **Android WorkManager** or local system alarm scheduler frameworks. Reminders are scheduled locally and trigger localized push alerts directly on your operating system at the exact specified time, requiring zero battery-draining socket connections.
Yes. Secure Dialer contains an offline, on-device SQLite blocklist. If an incoming number matches any entry in your local blocklist, the app automatically declines the call at the system level. This filtering happens entirely on-device without exposing the caller's identity or forwarding telemetry data to any third-party spam-tracking databases.
Yes. Secure Dialer fully queries active subscription lines on multi-SIM hardware. When starting an outbound call, the dialer prompts you with a clean dialog to choose the calling SIM, or follows your preset standard carrier SIM preferences established in the system or dialer settings.
These permissions are strictly essential to fulfill primary telephone handler roles. Android requires READ_CONTACTS to resolve names, READ_CALL_LOG to show your recent calling records, and WRITE_CALL_LOG to let you delete elements. Because our app does not possess network permissions, we guarantee this data cannot be leaked.
Yes! Secure Dialer features a password-protected **Local Backup & Export** engine inside Settings (powered by BackupRestoreManager). This engine compiles your blocklist, configurations, and speed-dials into an encrypted payload using **PBKDF2 derivation** and **AES-GCM encryption** keys generated from your custom password. You can export this backup string as a text file and restore it securely on another device.
No. Secure Dialer contains **zero ads, zero tracking scripts, and zero analytical trackers** (such as Firebase Analytics or AdMob). The app is completely free, does not offer premium subscriptions, and respects your privacy absolutely from the core architecture up.
The codebase is **100% open source under the GPLv3 license**. We invite privacy advocates, cybersecurity firms, and open-source developers to fully audit our repository, check the Room SQL database schemas, inspect the KeyStore encryption classes, verify the complete lack of internet permissions, and compile their own build from source.
Document
Download Secure Dialer (v1.3.0)
Choose the optimal build package or universal binary below
1. Select Build Architecture
Universal BuildAll CPUs
Compatible with all physical devices and emulators. (Larger file)
~16.7 MB
ARM64-v8aRecommended
For modern 64-bit phones (Pixel, Galaxy, modern devices).
~7.3 MB
ARMeabi-v7a32-bit CPU
For older 32-bit Android phones and legacy devices.
~6.0 MB
x86_64PC Emulator
For 64-bit Android Virtual Devices (AVD) running on computers.
~7.7 MB
x8632-bit PC
For legacy 32-bit computer-based emulator environments.
