The concept Web of Things (WoT) goes well beyond the emphasis on the Internet as a means of sharing data, instead of introducing all resources and connections involving computers, data, and people to the Web. It, therefore, focuses on a range of problems and opportunities, thus paving the way for several exciting industries applications. In cryptography a range of main characteristics of chaotic systems such as non-linearity, initial condition sensitivity, and mixing properties are available. These characteristics provide an essential connection between cryptography and chaos. GOST is the Russian norm of encryption. GOST block cipher is based on secret key secrecy. However, when the encryption process with the same key is used for plaintext, the same cipher text is created. Message replication can be easily detected by an adversary who is a bad link in every communication. In this paper, we propose to use a 5d chaotic system combined with GOST block cipher to create a new secure Web of Things (WoT) cryptography system. GOST is a symmetric block cipher. It is the basis of most secure information systems in Russia. The 5D chaotic system was used to generate chaotic random keys that used in the GOST algorithm to provide security as a higher strength to increases randomly. The National Institute of Standards and Technology (NIST) designed a set of fifteen statistical tests and modifies key schedule as security operations.