Frequency Analysis
A cryptanalysis technique used to break encryption by analyzing the frequency of characters.
Understanding Frequency Analysis
This technique relies on the fact that certain letters and words appear more frequently than others in most languages. Attackers analyze the frequency of characters, digraphs (two-letter combinations), and trigraphs (three-letter sequences) to guess the original plaintext.
How Frequency Analysis Works
Letter Frequency Comparison – Matching encrypted text patterns with known letter frequency distributions (e.g., in English, ‘E’ is the most common letter).
Statistical Pattern Recognition – Identifying repeated patterns in ciphertext that correspond to common words (e.g., "the" or "and").
Contextual Analysis – Using grammatical structures and context clues to refine decryption attempts.
Best Practices for Protecting Against Frequency Analysis
1. Use Modern Cryptographic Algorithms
AES and RSA encryption prevent statistical attacks.
2. Increase Randomness in Encryption
Polyalphabetic ciphers and pseudorandom padding reduce predictability.
3. Avoid Short or Predictable Passwords
Longer, complex passwords resist statistical attacks.