Software Characteristic Challenge Electronic Seal System is an electronic seal system developed with national patent technology. She can directly affix electronic seal and handwritten signature on documents (Word), spreadsheets (Excel), web pages (HTML) and PDF documents. Challenge the electronic seal system and detect whether the document has been tampered with or destroyed by advanced PKI technology. When it is detected that the document content has been tampered with or destroyed, the electronic seal will automatically become invalid and warn the user. Only the key with electronic seal (stored in an unrepeatable smart card, similar to a door key) can be used for electronic signature. The main technical characteristics of challenging the electronic seal system: 1. The electronic seal system developed with national patent technology is in a leading position in China. 2, can be directly in the Word, Excel, Html, PDF handwritten signature, electronic signature. 3. Protect the contents of documents from being modified and undeniable, and strictly abide by the requirements of other relevant laws. 4. Digital certificates of third-party CA certification centers (such as VeriSign, Entrust, China Financial Certification Center, etc.). ) can be used, also can use the digital certificate of internal CA center. 5. Adopt the international standard digital certificate format to ensure the compatibility of the system with other digital systems. 6. Using high-strength SHA-5 12, RSA/ 1024 electronic signature algorithm, the security is higher. 7. You can view the digital certificate of the signer of the electronic signature or the digital certificate of the company to which the signer belongs. 8. If the content of the document changes slightly, the electronic seal can immediately detect that the document has been modified and the electronic seal is invalid. 9. Support online verification of the legality of electronic seals. 10, supporting document locking, prohibiting moving signature, printing, copying and saving 1 1, supporting rotating signature, making electronic seal closer to physical seal function. 12, supporting up to 100 smart card devices produced by different manufacturers.