Bronze Tiger Tally of Marquis Lin Yuan
The Bronze Tiger Tally of Marquis Lin Yuan is an artifact dating back to the early Western Han Dynasty (206 B.C.-A.D. 25). It is so tiny that an adult can hold it in one hand. The tally is in the shape of a lying tiger, with its head protruding forward and its tail rolling upwards. Square grooves on the sides verify authenticity by interlocking.
A tiger tally consists of two halves, with one half held by the monarch and the other by the commanding officer as a symbol of military authority. The officer would only accept orders accompanied by interlocking the other half.
Tiger tallies originated in the Spring and Autumn Period and were most commonly used in the Warring States Period and Qin and Han dynasties. Most were cast in bronze and engraved with inscriptions.
One can read information from the inscriptions on only one half of an early tiger tally. From the Han Dynasty (206 B.C.-A.D. 220), inscriptions were usually carved on the tiger's back separated into two halves, and the message they carry can be legible only when the two halves are pieced together, thus enhancing the confidentiality.
With nine incomplete characters on the tiger's back, this is the left half of a tiger tally owned by Marquis Lin Yuan who commanded the army. To move the troops, the emperor needed to send an envoy with the right half to the garrison of Marquis Lin Yuan, who would accept the order when the two halves matched.
The unique design and craftsmanship of the tiger tally provides valuable references to the study of the military authority system and army management methods in ancient China. It is also the physical evidence of early encryption methods in the military of ancient China, and its authenticity verifying approach is similar to modern encryption techniques.
临袁侯铜虎符
临袁侯铜虎符，为西汉早期制品，体量小巧，成年人一手可握。虎呈俯卧状，昂首向前，虎尾向上卷起，侧面有方形凹槽，用于对合时验证真伪。
虎符是将完整的虎形对半分开，一半在君王手中，一半作为军权凭证授予将领，如需调兵，要两半合一。虎符最早出现于春秋时期，盛行于战国秦汉，多用青铜铸成，再刻上文字。
早期的虎符只有一半也可读出信息，自汉代起虎符多将文字置于虎的脊背骑缝处，合符才能读出全部内容，保密性更强。由这件虎符背上的九个错银半字，可知此虎符为左半部分，在统军的临袁侯手中。如需调动军队，君王须派使臣持右半虎符前往临袁侯驻地，合符无误即可发兵。
虎符独特的设计和工艺是研究中国古代兵权制度和军事管理方式的珍贵资料，同时也是中国古代早期军事保密方法的实证，其配对验证思路与现代保密技术有异曲同工之处。
