Learn the classic Vigenere cipher with Vigenere Cipher Trainer — a hands-on tool to encrypt, decrypt, and practice polyalphabetic ciphers. Whether you are studying classical cryptography, preparing for a security course, or simply curious about historical ciphers, this app helps you understand how the Vigenere cipher works, step by step. Train with Letter Shifts, Decode Words and Speed Round challenges, and explore the full Vigenere table. Works fully offline — no account required.