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Explore practical guides for classical ciphers, encoding, number systems, formulas, examples, and browser-based tools
Guide Categories
Caesar Cipher
Articles about Caesar cipher and shift-based encryption methods
Vigenere Cipher
Polyalphabetic substitution cipher tutorials and guides
Playfair Cipher
Digraph substitution cipher implementation and analysis
Affine Cipher
Mathematical substitution cipher using linear transformations
Hill Cipher
Matrix-based polygraphic substitution cipher tutorials
Vernam Cipher
One-time pad and perfect security encryption methods
Beaufort Cipher
Self-reciprocal variant of Vigenere cipher guides
Atbash Cipher
Ancient Hebrew mirror substitution cipher tutorials
Pigpen Cipher
Geometric symbol-based substitution cipher guides
Polybius Cipher
Coordinate-based ancient Greek encryption methods
Keyword Cipher
Monoalphabetic substitution cipher tutorials and cryptanalysis guides
Converters
Number system, encoding, hashing, and random number guides
Baconian Cipher
Francis Bacon's binary steganographic cipher tutorials and guides
Porta Cipher
Della Porta's 13-table reciprocal polyalphabetic cipher guides
Gronsfeld Cipher
Numeric-key Vigenere variant cipher tutorials and analysis
Trithemius Cipher
Tabula recta and progressive-key cipher guides
Alberti Cipher
The first polyalphabetic cipher disk system tutorials
Homophonic Cipher
Homophonic substitution cipher tutorials and Zodiac Killer analysis
Four-Square Cipher
Delastelle's digraph encryption system tutorials and guides
Autokey Cipher
Self-keying Vigenere variant cipher tutorials and cryptanalysis
Quagmire Cipher
ACA's advanced polyalphabetic substitution cipher with four variants
Morse Code
Morse code encoding, translation, history, and learning guides
Frequency Analysis
Letter frequency analysis, cryptanalysis techniques, and cipher breaking guides
Running Key Cipher
Running key cipher tutorials using book passages as encryption keys
Straddling Checkerboard
Straddling checkerboard cipher and VIC cipher Cold War espionage guides
Recent Articles
How Cryptographic Hash Functions Work — MD5 vs SHA-256 vs SHA-512 Explained
Complete guide to cryptographic hash functions covering MD5 vs SHA-256 vs SHA-512 comparison, how hashing works internally, collision attacks, password hashing best practices with bcrypt and Argon2, HMAC authentication, and applications in blockchain, TLS, and Git.
How to Read Binary Code: Complete Guide to Binary Translation
A complete guide to reading binary code, covering bits and bytes, positional notation, step-by-step decoding, ASCII and Unicode encodings, common words in binary, Python and JavaScript examples, and comparisons with other number systems.
Base64 Encoding Explained: How It Works, Data URIs & JWT
A complete guide to Base64 encoding, covering the 3-byte to 4-character algorithm, padding, 33% size overhead, data URIs, JWT tokens, MIME email, HTTP Basic Authentication, PEM certificates, URL-safe Base64, and examples in JavaScript, Python, Java, PHP, Go, C#, and the CLI.
URL Encoding Guide: Percent Encoding, RFC 3986 & Common Mistakes
A complete guide to URL encoding, covering the percent-encoding algorithm, RFC 3986 character classes, reserved and unreserved characters, %20 versus + for spaces, encodeURI versus encodeURIComponent, double-encoding bugs, URL encoding versus HTML encoding, and examples in seven languages.
Hex to Text Conversion: ASCII Table, Hex Dumps & Programming Guide
A complete guide to hex-to-text conversion, with an ASCII hex table for printable characters, how to read hex dumps, UTF-8 multibyte encoding, file magic bytes, Python, JavaScript, and CLI examples, and common hex values useful to developers.
Affine Cipher Mathematics: Complete Guide to Modular Arithmetic & Encryption
A complete guide to the mathematical foundations of the Affine cipher covering modular arithmetic, modular multiplicative inverses, key validation, the encryption and decryption formulas, worked examples, and cryptanalysis techniques.