The centralized storage and processing of big data increases the risk of communication data leakage, and the security of user communication transmission has become a current research hotspot. Therefore, to improve the efficiency of existing anonymous communication schemes, this study designs an anonymous identity-based encryption algorithm based on the Decisional Bilinear Diffie-Hellman. An anonymous communication model for small-scale users is further proposed. When the data size was 100 MB, the proposed algorithm had an upload time cost of approximately 827.3 ms and a download time cost of 208.4 ms. The proposed method reduced communication time by 37.86%, 30.43%, and 16.88% compared with other methods, respectively. Under 20 multiple server attacks, the average resistance time was as high as 22.78 s, which increased by 30.02%, 25.65%, 52.07%, 488.63%, and 78.67% compared with the other 5 methods, respectively. The anonymous identity-based encryption algorithm can improve the security of information transmission, and the small-scale anonymous communication model strengthens the privacy and security of user communication processes, which is significant for improving the security of big data servers.