[Cryptography] Statement from Attorney General William P., Barr on Introduction of Lawful Access Bill in Senate

[Arnold Reinhold]

On Wed, 1 Jul 2020 11:12 Phillip Hallam-Baker wrote:

> The attempt to regulate use of codes is rather older and the concern was
> commercial. The ITU was originally formed to co-ordinate regulations
> preventing use of codes on telegraph systems.
> 
> The concern was purely commercial. Telegrams were priced by the word and
> codes were used to reduce costs. …

This concern led to perhaps the greatest failure in cryptographic history. To minimize lost revenue, telegraph companies charged a higher price for code words. At some point they got tired of arguing about what constituted a code word vs a foreign word and simply charged more for words that were unpronounceable. The pre-WW II Japanese Foreign Office wanted to save money on the many encrypted cables it sent and had their cipher machines (which worked on the English alphabet for compatibility with the international telegraph network) designed so they could encrypt vowels into vowels and consonants into consonants, thereby preserving pronounceability. When the more secure Type B system, code named PURPLE by the U.S., was introduced, the Army Signal Intelligence Service quickly noticed that the ciphertext showed the same 6 vs 20 letter grouping that they knew from the earlier broken Type A RED code. They were soon able to break the 6s code which gave them some cribs that eventually led to breaking the much stronger 20s cipher, after some 18 months of hard work. 

The initial break was reported by 27 year old Genevieve Grotjan at about 2 pm on September 20, 1940. The 80th anniversary of that break is coming up and deserves some commemoration, both to honor a woman whose technical achievements helped change history (she also made a major contribution to breaking Soviet ciphers in the VENONA project) and as a warning about the dangers of non-cryptographer bureaucrats insisting on changes that weaken encryption systems.  


Arnold Reinhold