## Bigram 750 challenge solved, new world record set

Last week, I introduced a 750-letter ciphertext created with a bigram substitution. Jarl Van Eycke and Louie Helm have now solved this challenge. As far as I know, this is the shortest bigram cipher challenge ever broken.

## Solve this bigram challenge and set a new world record

Jarl Van Eycke and Louie Helm recently solved a bigram substitution ciphertext consisting of 1000 letters – the shortest one ever broken. Now I have created a 750-letter challenge of the same kind.

## Can you break this bigram substitution from the Cold War?

George Lasry has found an interesting collection of challenge ciphers, probably used to train codebreakers during the early Cold War. Today, I’m going to present one of these challenges.

## Bigram 1000 challenge solved, new world record set

A few weeks ago, I introduced a 1000-letter ciphertext created with a bigram substitution. Jarl Van Eycke and Louie Helm have now solved this challenge and set a new world record.

## Solve this bigram challenge and set a new world record

Blog reader Norbert Biermann has recently solved a bigram substitution ciphertext consisting of 1346 letters – the shortest one ever broken. Here’s a 1000-letter ciphertext of the same kind.

## Norbert Biermann solves bigram challenge and sets a new world record

In July, I introduced a bigram substitution challenge consisting of 1346 letters. Norbert Biermann has now solved it. It’s the shortest ciphertext of this kind that has ever been broken.

## Can you solve this bigram challenge and set a new world record?

Substituting letter pairs (also known as bigrams or digraphs) is an encryption method invented in the 16th century. Can you break a new challenge I have made?

## Bigram substitution: An old and simple encryption algorithm that is hard to break

Substituting letter pairs (bigrams) is an encryption method that was already known in the 16th century. Is it still secure today?