Language redundancy and ●●●●● ●●●● ●●0 Cryptanalysis ●●● ●●●● o human languages are redundant o letters are not equally commonly used in English, E and T are the two most common letters then AO,I,N,S, H, R(5%) other letters are fairly rare, e.g., V,KJ, X, Q, 2 (<1%) have tables of single, double triple letter frequencies COMP4690. HKBUCOMP4690, HKBU 14 Language Redundancy and Cryptanalysis ⚫ human languages are redundant ⚫ letters are not equally commonly used ⚫ in English, E and T are the two most common letters ⚫ then {A,O,I,N,S,H,R} (>5%) ⚫ other letters are fairly rare, e.g., {V,K,J,X,Q,Z} (<1%) ⚫ have tables of single, double & triple letter frequencies