100% Web Crypto API Sisi Klien · Nol Unggahan Server · Siap Digunakan Offline (Air-Gapped)

2FA Online Authenticator

Autentikator standar RFC 6238 TOTP. Menghitung kode dinamis 6 digit dan kode QR Google Authenticator secara lokal di browser Anda dengan latensi nol.

🔑 2FA Dynamic Code Generator

Mendukung kunci tunggal dan mode batch multi-baris · Hitung mundur langsung 30 detik

RFC 6238 HMAC-SHA1
Sanitasi huruf besar & spasi otomatis
Sampel Uji:
Kode Sandi 2FA
TOTP · 30s
Kode Sandi Sekali Pakai
000 000

Diperbarui otomatis setiap 30 detik

30
detik tersisa
🛡️ Jaminan Zero-Knowledge (100% Sisi Klien)

All secret keys and generated passcodes are processed locally in your browser sandbox using the standard Web Crypto API. No data is ever transmitted to or stored on external servers.

Pusat Keamanan · Panduan 2FA-Tool

Panduan Keamanan & Pengerasan 2FA Pilihan

Kepatuhan kriptografi standar tinggi dan privasi pengguna tanpa kompromi

Jelajahi Semua 12 Panduan
🧰

Mengalami masalah format Base32 atau pergeseran jam perangkat?

Explore our specialized 2FA Security Toolbox: Base32 Key Auto-Fixer, otpauth:// URI Inspector, and millisecond-accurate NTP clock drift detection.

Buka Alat Keamanan →
Tinjauan Arsitektur

Perbandingan Metode 2FA: Mengapa TOTP adalah Standar Emas

Comparing security levels, SIM swapping resistance, cost, and availability

Metode Tingkat Keamanan Kekebalan SIM Swap Mendukung Offline Biaya Kenyamanan Kasus Penggunaan Utama
★ TOTP (Utilitas Ini) Tinggi (Disarankan) Kebal (Tanpa Transmisi Seluler) 100% Offline Gratis (Web / Aplikasi) Sangat Tinggi Google, GitHub, AWS, Binance
Kode Verifikasi SMS Rendah hingga Sedang Rentan (Pembajakan SIM) Memerlukan Sinyal Seluler Rendah (Kartu SIM) Tinggi Login konsumen lawas
Kode Verifikasi Email Sedang Tergantung keamanan email Memerlukan Internet Gratis Sedang Cadangan alternatif sekunder
FIDO2 / Kunci Perangkat Keras Tinggiest (Anti-Phishing) Kebal Didukung $25 - $70 (Perangkat Keras) Sedang (Must Carry) Tinggi-value enterprise infra
Langkah demi Langkah

Panduan Pengaturan Platform & Aturan Cadangan

Cara mengaktifkan 2FA dan menyimpan kunci pemulihan di platform utama

🐙 GitHub DevOps

Go to Settings -> Password and authentication -> Two-factor authentication. Click Enable 2FA, choose "Set up using an app", and copy the Base32 plaintext key.

Critical: Download and store your 16 Recovery Codes in an offline secure location!
🔍 Akun Google Ecosystem

Navigate to myaccount.google.com -> Security -> 2-Step Verification. Scroll down to "Authenticator app" and click "Can't scan it?" to copy the 32-character plaintext secret.

Critical: Configure a backup phone number or security key to prevent single point of failure.
💰 Binance & Bursa Finance

Under Security -> Authenticator App, click Enable. Write down the 16-character Reset Key on paper and store it in a physical safe.

Rule: Never save exchange 2FA secret keys in unencrypted cloud photo albums!
Logika Kriptografi

Bagaimana Cara Kerja Algoritma RFC 6238 TOTP?

Mathematical steps turning shared secrets and Unix timestamps into synchronized codes

The Time-Based One-Time Password algorithm (TOTP) is defined in IETF RFC 6238. It converts continuous timestamps into discrete 30-second counters and executes HMAC-SHA1 hashing:

Langkah 1

Kuantisasi Langkah Waktu

Bagi detik Unix saat ini dengan interval 30 detik: T = floor(Epoch / 30)

Langkah 2

Decoding Base32

Ubah string Base32 (RFC 4648) kembali menjadi byte kunci kriptografi mentah.

Langkah 3

Hashing HMAC-SHA1

Hash the 8-byte big-endian time counter with the secret key to yield a 20-byte digest.

Langkah 4

Pemotongan Dinamis (Dynamic Truncation)

Use the lowest 4 bits of the last byte as an offset to extract a 31-bit unsigned integer.

Langkah 5

Modulo 10^6

Take modulo 1,000,000: Code = Value % 10^6, zero-padded to 6 digits.

Troubleshooting

Code Shows "Invalid"? 4 Common Causes

99% of 2FA validation errors arise from local clock drift or character confusion

1 System Clock Drift (Most Common)

If your computer or phone clock drifts by even 15 seconds, your code falls into a different time window. Solution: Enable "Set Time Automatically (NTP)" in your OS settings.

2 Base32 Character Confusion

Base32 contains A-Z and 2-7. It never contains 0, 1, 8, 9. Do not confuse letter O with number 0, or letter I/L with number 1.

3 Using an Outdated Secret

If you clicked "Reset 2FA" on the platform multiple times, previous keys become invalid instantly. Ensure you are using the most recently generated secret.

4 Timing Expiry During Submission

Submitting when the progress bar has only 1-2 seconds left may cause the code to expire in transit. Wait for a fresh 30-second cycle.

Ecosystem

Recommended Authenticator Apps

Choose the optimal 2FA client for your security workflow

Google Authenticator

Most Popular

Clean interface, supports Akun Google cloud backup, or can be used in offline local-only mode.

Best for: Everyday users on Android and iOS.

2FAS (Open Source)

Recommended

100% open-source, zero data tracking. End-to-end encrypted backup to iCloud/Google Drive with browser extension pairing.

Best for: Privacy-focused individuals and developers.

1Password / Bitwarden

Productivity

Stores TOTP keys alongside passwords for seamless one-click auto-fill across all browsers and desktop apps.

Best for: Managing hundreds of enterprise accounts.
FAQ

Pertanyaan yang Sering Diajukan (FAQ)

Detailed answers regarding 2FA security, offline operation, and batch formatting