NazoRaku - Cipher Puzzles
Solve it. Understand ciphers.
Free · In-App Purchases · Designed for iPad. Not verified for macOS.
Ciphers, solved by playing. Crack classic and modern ciphers from Caesar to RSA and hashing—work out the key, use frequency analysis, then learn how each works.
A puzzle game where you UNDERSTAND ciphers by solving them - not by reading about them.
From the Caesar cipher to RSA and hashing, crack classic and modern ciphers one stage at a time, and the way each cipher works clicks into place. Slide to find the key, spot letters with frequency analysis, reverse-lookup a grid - relive that "aha" moment of decryption again and again.
[ Classic ciphers - free, 40 puzzles ]
- Caesar (10) - Shift letters; work out the shift from the crib and enter it
- Vigenere (10) - Polyalphabetic with a keyword; guess the key
- Substitution (8) - One-to-one swap; crack it with frequency analysis
- Transposition (6) - See through the reordering
- Polybius Square (6) - Letters to numbers via a 5x5 grid; reverse-look up
[ Modern ciphers ]
- XOR (6) - Exclusive OR; XOR with the key to recover the text (free)
- Public-Key (RSA, simplified) - Lock with the public key, find the message
- Hash Function - Feel one-wayness; find an input that collides to the same output
- Block Cipher (AES-style) - Step through add-key, substitute, and permute rounds
[ Features ]
- Explanation right after you solve - history, real-world usage, weaknesses, and the bridge to modern tech
- Staged hints - a free recap first, then gradual reveals when stuck (keeps the "I solved it" feeling)
- No ads at all while you are solving a puzzle - designed to preserve focus
- Achievement badges and stats for collection
- Universal app for iPhone and iPad
- Japanese and English (UI, puzzle text, and hints; follows the device language)
- Ciphertext shown beautifully in a monospaced font
[ Who is this for ]
- Anyone who loves puzzles and riddles
- Students and engineers curious about cryptography and security
- People who want quick brain-training in spare moments
[ Part of the Raku Series ]
The third information-systems title of the Raku Series. Knowledge from ARURAKU (algorithms) and DATARAKU (data structures) pays off in NazoRaku's decryption - hashing and modular exponentiation tie ciphers back to the fundamentals.
[ Note on pricing ]
Free to play. All classic-cipher stages and the modern-cipher intro are free. Hints, ad removal, the Modern Cipher Pack, and an all-in-one Premium are available as in-app purchases. No ads are ever shown while you are solving a puzzle.
Ratings & Reviews
- This app has not received enough ratings or reviews to display an overview.
The developer, Fuji Bit Inc., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Identifiers
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Identifiers
- Usage Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Provider
- Fuji Bit Inc.
- Size
- 4.9 MB
- Category
- Puzzle
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- Contains
Advertising
- In-App Purchases
Yes
- Premium (All-in-One) USD 17.99
- Modern Cipher Pack USD 6.99
- Remove Ads USD 4.99
- 10 Hint Tickets USD 6.99
- 1 Hint Ticket USD 0.99
- Copyright
- © 2026 Fuji Bit