The thread on Zodiackiller.com also points to the derived letters representing this portion of the cipher after it was solved, the GYKE becoming AUSE. It is then, not a great leap to form GYKEAUSEKEY using these two portions.
In the San Francisco Chronicle letter sent on July 31st 1969 he tempted the observer with the lines "I want you to print this cipher on the front page of your paper. In this cipher is my idenity".
When cracked by Donald Gene and Bettye June Harden several days later it revealed little in the way of unmasking the Northern California killer, but was the Zodiac a master of wordplay, rather than a complete liar, after all he did not say 'once the cipher was cracked we would have his identity', moreover his identity was in the cipher, which GYKE certainly was.
His wordplay comes into effect in the follow up Debut of Zodiac Letter on August 4th 1969, where upon he taunts the police, stating "By the way, are the police having a good time with the code? If not, tell them to cheer up; when they do crack it, they will have me". Again this appears another empty promise, but it certainly was not, as on the 17th line of the 408 cipher,
So can we find a clue to Richard Gaikowski in the 340 cipher as well as the 408 cipher and bolster up the argument that indeed the Zodiac did leave clues to his identity in both of the main ciphers.
Tantalizingly we have the letters AIK on the 20th and final line of the 340, but the G unfortunately nowhere in sight, so we will fetch it from the 408 instead. As we stated earlier GYKE is positioned on the 20th line of the 408 cipher, 4 to 7 symbols into the line, so we will take this and transfer it to exactly the same position on the 20th line of the 340 cipher, 4 to 7 symbols into the line and place it over the existing symbols, to form GYKES ZODIAC or GYKAUSEKEYS ZODIAC. SEE BELOW.
It is also now possible to form GAIK running from left to right, but does it hint towards the identity of the Zodiac Killer and Richard Gaikowski being one and the same, no, it just shows what an amazing tool the art of deception and mathematics can be when one has a specific objective in mind.