The article describes the possibility to refuse the direct transfer of the key from the sender to the recipient in the synchronous stream encryption scheme. We suggest creating a table of correspondence between the key information K, and the time of sending an email or phone call. The sender will have one instance of such a table, and the recipient will have another. The format of the key information in the simplest case includes the PRNG key itself, which determines the logic of operation of the PRNG nonlinear function, the code of the type of the used PRNG nonlinear function, and the PRNG design code. We offer 2 ways of interaction between the sender and the recipient of messages. Consider two possible options for encryption schemes: when the superposition of a sequence from the output of the PRNG on the input sequence is performed by the XOR operation, and when the encryption process is performed with a stochastic transformation of R, and the operation decryption operation backward stochastic transformation R-1. We present the scheme of one of the simplest possible variants for constructing the block R of the stochastic transformation.