Cipher

A daily cryptography puzzle app

Solve a new cipher every day — binary, Caesar, hex, XOR, and more. Track your streak, unlock your archive, and sharpen your code-breaking skills.

Get it on Google Play View update log

Experience

From the daily puzzle to learning, packs, archives, and advanced stats, Cipher provides a complete cryptography loop.

Cipher home screen in Hacker theme

New cipher daily

Crack today's puzzle

Cipher challenge screen in Hacker theme

Can you crack it?

Decode clues with hints

Cipher solved challenge screen in Hacker theme

Learn after every solve

See stats, answers, and explanations

Cipher puzzle pack screen in Hacker theme

Puzzle packs

Themed code-breaking adventures

Cipher learn screen in Hacker theme

Learn the ciphers

Examples, guides, and tools

Cipher archive screen in Hacker theme

Replay the archive

Every past puzzle in one place

Cipher stats screen in Hacker theme

Track your progress

Streaks, times, and advanced stats

Daily Puzzles & Packs

  • Daily Challenge: A fresh cipher every day — 5 attempts, 3 hints, and interactive onboarding.
  • Puzzle Packs: Themed collections from beginner sets to spy thrillers, history, space, and fiendish expert chains.
  • The Archive: Replay every past puzzle by category — the last 7 days free, the full history with Pro.
  • Streaks: Build a daily solving streak, with streak freezes to protect your run.

Learn, Track & Personalize

  • Learn: Built-in lessons for each cipher with worked examples and a hands-on "try it yourself" widget.
  • Track Progress: Solve rate, current streak, best times, and average attempts — plus advanced Pro breakdowns and a full-year heatmap.
  • Themes: Hacker (matrix green on black), Dark, Light, or follow your system setting.
  • Offline & Private: No account needed and no internet required to play.

Cipher Types

Every challenge tests a different technique. Caesar & ROT letter shifting; Binary, Decimal & Hex ASCII decoding; Vigenère & Autokey keyword ciphers; plus Morse, Atbash, Affine, rail fence, XOR, and many more.

Go Pro

Upgrade to unlock the full archive, unlimited hints, advanced stats, an ad-free experience, and the two-way Toolbox — encode and decode any supported cipher instantly. Available as monthly, yearly, or lifetime, with hint packs and ad removal also offered separately. Earn Google Play Games achievements for first solves, long streaks, flawless runs, and major milestones along the way.

Engineering Highlights

Update Log

Version 1.0 Latest
  • Official 1.0 Production Release.
  • Added clarity on Google Play Games and device backups.
  • Added a vector-based testing system for encryption consistency.
  • Implemented database migration guards to prevent user data loss.
  • Added automated structural and leakage tests for all puzzle content.
  • Verified daily challenge runway and uniqueness through 2027.
Version 0.41
  • Redesigned the Pro Cipher Toolbox with search and selectable results.
  • Improved reminder reliability and scheduling precision on app launch.
  • Added 6 new themed puzzle packs, including Bletchley Park and Ghost Protocol.
  • Extended daily puzzles through the end of 2027 with 322 new challenges.
  • Added special holiday-themed puzzles for festive days throughout the year.
Version 0.40
  • Added detailed plan status and renewal info to the Settings Pro section.
  • Fixed failed or cancelled purchases to display clear error messages.
  • Added a one-tap resubscribe option in Settings for lapsed Pro accounts.
  • Added Share, Rate, and Support options under Settings Help.
  • Added a year-long activity heatmap for Pro users to track daily solve history.
  • Added a friendly placeholder message when the Daily Archive is empty.
Version 0.39
  • Fixed a bug causing the notes panel to behave incorrectly.
Version 0.38
  • Added "Next Challenge" button to results for seamless play.
  • Integrated Play In-App Review prompt after 3 successful solves.
  • Launched Cipher Toolbox (Pro) for full two-way encoding/decoding.
  • Added interactive "try it yourself" fields to all Learn lessons.
  • Included new worked examples for Columnar and Multi-step lessons.
  • Implemented CipherEngine.kt with 3,100+ test vectors for accuracy.
Version 0.37
  • Included puzzle packs in overall statistics.
  • Fixed charts to display solves chronologically with labels.
  • Removed zero-second legacy data for accurate average times.
  • Updated results and share text for unlimited-attempt packs.
  • Restricted speed achievements to timed puzzles.
  • Added dynamic weekday labels to the home streak tracker.
  • Sorted data by ID to ensure stats reflect the latest solves.
  • Revamped the Treasure Island pack with enhanced animations.
Version 0.36
  • Added themed Puzzle Packs (free and premium).
  • All puzzles now maintain your daily streak.
  • Added smart reminders and streak expiry warnings.
  • Reduced ad frequency for free players.
  • Refreshed stats with a cleaner solve-time chart.
  • Pro and Lifetime users get all packs for free.
  • Improved price loading and light mode contrast.
Version 0.35
  • Added 120 brand-new cryptographic puzzles.
  • Introduced a new Learn tab featuring 15 comprehensive lessons grouped by difficulty.
  • Added self-contained detailed views for lessons with step-by-step worked examples.
  • Updated and refined various interface colors.
Version 0.34
  • Fixed hint violations across 39 puzzles to prevent premature answer reveals.
  • Fixed attempt feedback leaks across 26 puzzles by replacing answers with guided clues.
  • Replaced explicit solution steps with progressive hints that encourage solving.
Version 0.33
  • Cleaned up puzzle content, answer leaks, and spoilers.
  • Disabled daily reminders if today's puzzle is already solved.
  • Added a "Reveal Answer" button to the results screen.
  • Introduced an in-game Worksheet with Notes, A-Z reference, and a Mod Calculator.
  • Added streak rewards (+1 hint token every 7 days) with progress tracking.
  • Expanded the tutorial with new feature guides, replayable from Settings.
Version 0.32
  • Fixed layout overlap in the daily reminder settings row.
  • Updated subscription management display to properly reflect lifetime purchases.
  • Fixed hardcoded dark backgrounds on light theme in the share preview and pro badge.
  • Corrected the vertical alignment of the tutorial page indicator dots.
Version 0.31
  • Updated the app icon with a fresh new design.
Version 0.30
  • Completed a deep audit of all 250 challenges to ensure strict schema adherence and high-quality content.
  • Reduced duplicate puzzles, adjusted polyalphabetic category distribution, and removed non-standard prompts.
  • Integrated Google Play Games Services, including 20 new unlockable achievements and a dedicated view button.
Version 0.29
  • Fixed a layout issue that caused a double status bar gap in the top app bar.
  • Automated the version name display in Settings using BuildConfig.
Version 0.28
  • Added a 4-theme system (Hacker, Dark, Light, System) with adaptive system bar colors.
  • Added a 6-page interactive onboarding flow with a live theme preview and a Caesar cipher demo puzzle.
  • Added a new Appearance section in Settings to change themes at any time.
  • Updated various challenges.
Version 0.27
  • Added an auto-freeze feature that automatically protects streaks of 7 days or more.
  • Replaced the streak restore dialog with a full-screen, non-dismissible overlay.
  • Fixed a billing issue where the restore screen would disappear if a purchase was cancelled.
  • Added a button to re-enter the streak restoration screen after skipping it.
Version 0.26
  • Added standard in-app purchases to remove ads.
  • Added purchase options for hint token packs.
  • Added a purchase option to restore your daily puzzle streak.
Version 0.25
  • Updated the scoring formula for performance stats.
  • Increased the size of the 14-day solve times bar chart.
Version 0.24
  • Reverted homepage title to original font spacing.
  • Changed average solve time icon to an hourglass.
  • Locked app orientation to portrait mode.
  • Fixed status bar icons to always remain white.
  • Redesigned subscription tab layout to remove empty blank space.
  • Added a smarter daily puzzle notification prompt with a maximum of 3 appearances.
Version 0.23
  • Added Archive category colors to homepage chips.
  • Fixed homepage title jitter with fixed-width glyphs.
  • Updated stats page to show unlimited hints for Pro users.
  • Aligned yearly subscription card height and layout.
  • Moved subscription savings badge inside the card to fix clipping.
  • Added dynamic localized savings calculations with a graceful fallback.
Version 0.22
  • Added Archive category colors for all 13 categories.
  • Redesigned the share card with new attempt-based square scaling and an in-app preview.
  • Added random taglines and Play Store link to shared/copied text.
  • Reduced the bar chart height for a more compact view.
  • Added advanced Pro stats (Perfect Solves, No-Hint Solves, Avg Hints / Solve, Total Play Time, and Performance by Difficulty).
Version 0.21
  • Added revamped challenges.
Version 0.20
  • Added revamped challenges.
Version 0.19
  • Revamped reference tables and facilitated access to them.
Version 0.18
  • Revamped the first 75 challenges completely.
  • Fixed challenge submit button colors.
  • Fixed bug where ads would show when subscribed to pro.
  • Fixed puzzle count in settings.
  • Added replayability feature in pro subscription pop-up.
  • Fixed all challenges to count towards the daily streak.
Version 0.17
  • Added replayability.
  • Added challenges.
  • Modified challenges.
Version 0.16
  • Added challenges.
Version 0.15
  • Bug fixes.
Version 0.14
  • Added daily notification option prompt to users.
Version 0.13
  • Bug fixes.
Version 0.12
  • Bug fixes.
Version 0.11
  • Bug fixes.
Version 0.10
  • Bug fixes.
Version 0.9
  • Added privacy policy dialog.
  • Pricing loaded from Google based off location.
  • Bug fixes.
Version 0.8
  • Added challenges.
Version 0.7
  • Fixed advertisement IDs.
Version 0.6
  • Bug fixes.
Version 0.5
  • Bug fixes.
Version 0.4
  • Bug fixes.
Version 0.3
  • Implemented all pro features.
Version 0.2
  • Initial release.