columnar transposition

14 examples (0.03 sec)
• Columnar transposition continued to be used for serious purposes as a component of more complex ciphers at least into the 1950s.
• This is simply a columnar transposition applied twice.
• During World War I, the German military used a double columnar transposition cipher, changing the keys infrequently.
• The groups were written in a square grid according to an irregular pattern and read off vertically, similar to a disrupted columnar transposition.
• For example, a simple substitution cipher combined with a columnar transposition avoids the weakness of both.
• Next, the fractionated message is subject to a columnar transposition.
• In a columnar transposition, the message is written out in rows of a fixed length, and then read out again column by column, and the columns are chosen in some scrambled order.
• Trying to find this permutation is essentially the same problem encountered when analysing a columnar transposition cipher: multiple anagramming.
• In fact, the code was a fractionating transposition cipher based on a substitution table of 100 groups of two figures each followed by a columnar transposition.
• A stronger way of constructing a mixed alphabet is to perform a columnar transposition on the ordinary alphabet using the keyword, but this is not often done.
• A single columnar transposition could be attacked by guessing possible column lengths, writing the message out in its columns (but in the wrong order, as the key is not yet known), and then looking for possible anagrams.
• The ADFGX and ADFGVX field ciphers were a modified polybius system with single order double columnar transposition and frequent key change, with letters optimized for Morse.
• In a regular columnar transposition cipher, any spare spaces are filled with nulls; in an irregular columnar transposition cipher, the spaces are left blank.
• Invented by Colonel Fritz Nebel and introduced in March 1918, the cipher was a fractionating transposition cipher which combined a modified Polybius square with a single columnar transposition.