certificationn.证明；认证；证书；鉴定certification of completion竣工合格证书certification by attainment以成绩鉴定水平Certification of Compliance遵守证书certification of maintenance维修证明Certification Administration证件管理certification marking system产品合格检验证明制度certification on tax payment纳税证明书certification and inspection发证检验certification characteristics认证特性Certification Data Processing证书数据处理

1. The code you submitted could not be authenticated.
   不能鉴别你输入的认证码。
2. Single bit and multiple bits diffusion code and the method of constructing authentication code and block cipher used with them is suggested in this paper.
   本文提出了单比特和多比特扩散码以及用它们构造认证码和分组密码的方法。