10 (3) Certification Authorities must justify adequate financial guarantee, allocated particularly for the payment of sums they may owe people who relied logically on the qualified certificates they issue, or an insurance that guarantees the pecuniary consequences of their civil professional responsibility. CHAPTER VI ELECTRONIC SIGNATURE Section 17. The advanced electronic signature shall have the same legal value as that handwritten signature and produce the same effects as the latter. Section 18. An advanced electronic signature must meet the following conditions: - the data related to signature creation shall be exclusively linked to the signatory and be under his exclusive control; each modification shall be easily detectable; it shall be created using a protected device whose technical characteristics shall be defined by an instrument of the Minister in charge of telecommunications; the certificate used to generate signatures shall be a qualified certificate. An instrument of the Ministry in charge of telecommunications shall determine the criteria of the qualification of certificates. CHAPTER VII ELECTRONIC CERTIFICATES AND SIGNATURES ISSUED BY CERTIFICATION AUTHORITIES Section 19. The certification authority that validated an electronic certificate may not retract. Section 20. (1) An electronic certificate issued outside the national territory shall produce the same legal effects as a qualified certificate issued in Cameroon provided that there is a decision recognizing the issuing authority by the Minister in charge of telecommunications. (2) The interoperability of qualified electronic certificates shall be regulated by an instrument of the Minister in charge of telecommunications. CHAPTER VIII ELECTRONIC DOCUMENT Section 21. Any person wishing to affix his electronic signature to a document can create the signature using a reliable device whose technical characteristics shall be determined by instrument of the Minister in charge of Telecommunications. Section 22. Any person using an electronic signature device must: - - take minimum precautions fixed by the instrument referred to in Section 21 above to avoid any illegal use of the encoding elements or personal equipment related to its signature; inform the Certification Authority about any illegitimate use of his signature; ensure the authenticity of all the data he declared to the electronic certification service