基于地理坐标和多重加密的农产品追溯编码设计

统一的追溯码是实现农产品溯源的基础，该文设计了一种由产地位置码、产品码、生产日期码、认证类型码等部分组成的农产品追溯码，其中位置码采用经纬度坐标，并根据中国经纬度跨度的特点将中国划分为6大区域，通过编码换算将13位的经纬度产地位置码转换为10位的相对位置码和1位位置标识码；分别对生产日期码、产品码进行转换，转换后的生产日期码变为3位相对日期码和1位时间标识码，变换后的产品码为5位；将位置标识码、时间标识码和认证类型码进行排列组合生成验证码。此编码码长较短、便于输入，加密性较强，应用此编码进行农产品溯源可实现在脱离数据库的情况下追溯出产地位置、生产日期、认证类型等与质量安全密切相关的关键信息。

Design of agricultural product trace coding based on geography coordinate and multi-encrypt

Uniform trace code is the basis for implementing traceability in farm products. A coding scheme that was composed of producing area position code, product code, production date code and attestation type code was designed. Producing area position code was consisted of 13 bits of longitude and latitude, which was converted to ten bits of relative position code and one position identifier by plotting six districts according to the range characters of longitude and latitude in China. Production date code was converted three bits of relative date code and one bit of date identifier. Product code was converted to five bits. The validation code was generated by permutation and combination of position identifier, date identifier and attestation type code. The design of this trace code has the characteristics of short code extent and strong encryption. With it for farm product traceability, the key quality safety information such as production area position, produce date and attestation type can be traced without the support of database.