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. 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.

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.