I propose (1) change the system immediately change the key every day, e.g. according to the date of the dispatch or according to the day of the year (1st... 365th day and so on) and so on)

change the system or its details every1* day (e.g., for a letter, 5 digits; one system: the first digit is fictitious; the second system: the last digit is fictitious, etc., etc.).

If one changes at least weekly (a) the key and (b) such details, one cannot decipher.

Lenin.

Fond 2, op. 2, d. 390 - autograph.

1* Further in the text is Lenin's note: "See [otri] turn", i.e. before this note Lenin wrote on the front side of G.V.Chicherin's letter, and the continuation on the back side.

1Lenin's note is a reply to the following letter of G.V.Chicherin: "August 21, 1920. Much-respected Vladimir Ilyich, I have always been skeptical of our ciphers, the most secret things are not reported at all and I have several times warned others against reporting such things. Comrade Kamenev's opinion that it is difficult to decipher is not correct. We know from our collaborator Sabanin, the son of an old decipherer of the Ministry of Foreign Affairs, that positively all foreign ciphers were deciphered by Russian decipherers. In the last period of Czarism there was not a foreign dispatch that was not deciphered, not because of treachery, but because of the art of the Russian deciphers. Foreign governments have more complicated ciphers than we use. If we are constantly changing the key, the system itself is known to tsarist officials and military men who are now in the camp of the White Guards abroad. I consider the deciphering of our ciphers to be quite permissible. The most secret messages should not be made otherwise than through specially dispatched persons.

Let us check by dates whether the ciphers mentioned by Kamenev are not forgeries. Only after we have received the text will it be possible to give a definitive answer to this question.

With Communist greetings Georgy Chicherin" (RCCHIDNI, f. 2, op. 2, d. 390).

See also doc. 254.