NazoRaku vs CipherStreet

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. Work out the key from a clue and enter it, spot letters with frequency analysis, reverse-look up a grid - relive that "aha" moment of decryption again and again. [ 9 ciphers, 57 puzzles ] 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 - 17 puzzles - XOR (6, free) - Exclusive OR; XOR with the key to recover the text - Public-Key, simplified RSA (4, Modern Cipher Pack) - Work out the number locked with the public key - Hash Function (4, Modern Cipher Pack) - Feel one-wayness; find an input that collides to the same output - Block Cipher, AES-style (3, Modern Cipher Pack) - Step through add-key, substitute, and permute, one move at a time [ Features ] - Explanation right after you solve - history, real-world usage, weaknesses, and the bridge to modern tech - Staged hints - the first level is free; reveal more step by step 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 (including your daily solving streak) - iPhone and iPad - Japanese and English (UI, puzzle text, and hints; follows the device language) - Ciphertext shown in an easy-to-read 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. [ Pricing ] Free to play. All 40 classic-cipher puzzles and the 6 XOR puzzles are free. In-app purchases: hint tickets (1 or a 10-pack), Remove Ads, the Modern Cipher Pack (unlocks public-key, hash, and block ciphers), and an all-in-one Premium (remove ads + all stages + unlimited hints). Non-consumable purchases can be restored from "Restore" in Settings / Store (hint tickets are consumable and cannot be restored). [ Ads ] To keep the app free, ads are shown at the bottom of screens such as Home and the stage list. No ads are shown on the screen where you solve puzzles. On first launch, the app asks whether ads tailored to your interests (personalized ads) may be shown. You can change this anytime from "Ad Settings" in Settings / Store.

CipherStreet is a story-driven puzzle game where every level is a real cryptographic cipher - from Caesar shifts to RSA public keys - wrapped in a cold-war spy thriller. Intercept encoded messages. Decode them with on-screen tools you discover, not tutorials you sit through. Unlock fragments of a decades-spanning conspiracy with every cipher you crack. By the end of ten chapters you'll have genuinely internalised the foundations of modern cryptography - roughly the first four weeks of a university course — without a single lecture. THE STORY A defector known only as The Architect has built a private intelligence network hidden inside ever more sophisticated ciphers. Your handler, Agent Kovács, sends each intercept with minimal context and maximum urgency. A mole. A missing codebook. A name that keeps reappearing across fifty years. Crack the codes before dawn. TEN CHAPTERS, TEN REAL CIPHERS • Caesar cipher: frequency analysis • Vigenère: the pattern inside the pattern • Rail Fence: transposition • Enigma (simplified): the crib attack that broke a war • Playfair: grid geometry • One-Time Pad: the perfect, unbreakable lock • Diffie-Hellman: sharing a secret in public • RSA: math as a lock • Hash functions: integrity, not secrecy • Steganography: messages hidden in plain sight WHAT MAKES IT DIFFERENT • Learn by doing: tools are discovered through play, never explained at you • Real, historically accurate cryptography, all running offline on your device • A genuine spy narrative with characters, twists, and a finale that recasts everything • No punishing fail states: get a cipher wrong and the story simply waits • Build and share your own encrypted intercepts; challenge friends to crack them FREE TO START Chapters 1–2 are completely free, no account required. A single one-time purchase unlocks chapters 3–10 and every cipher type in the Builder. No ads. No subscriptions. No tracking. The cipher is never the weakest link. The human always is.