Abugidas In most of the alphabets of India and Southeast Asia, vowels are indicated through diacritics or modification of the shape of the consonant. Source: Internet
All such ciphers are easier to break than once believed, as substitution alphabets are repeated for sufficiently large plaintexts. Source: Internet
As such, even today a Vigenère type cipher should theoretically be difficult to break if mixed alphabets are used in the tableau, if the keyword is random, and if the total length of ciphertext is less than 27.6 times the length of the keyword. Source: Internet
All of the aforementioned are alphabets. Source: Internet
But even with these alphabets, diacritics pose a complication: they can be regarded either as part of a single character containing a letter and diacritic (known as a precomposed character), or as separate characters. Source: Internet
A more systematic example is that of abjads like the Arabic and Hebrew alphabets, in which the short vowels are normally left unwritten and must be inferred by the reader. Source: Internet