Examples of foreign legislation concerning the effect and validity of digital signatures includes:
Uniform Electronic Transactions Act (UETA)
Electronic Signatures in Global and National Commerce Act (E-SIGN), at 15 U.S.C. 7001 et seq.
England and Wales
Electronic Communications Act 2000
Despite the fact that Hong Kong has introduced the Electronic Transactions Ordinance in 2001, there has been no decided case relating to the validity and use of digital signatures.
There are limited number of court decisions in foreign countries talking about the effect and validity of digital signatures or their related legislation:
re Piranha, Inc., 2003 WL 21468504 (N.D. Tex) (UETA does not preclude a person from contesting that he executed, adopted, or authorized an electronic signature that is purportedly his).
Cloud Corp. v. Hasbro, 314 F.3d 289 (7th Cir., 2002)http://www.emlf.org/Resources/cloud.pdf (E-SIGN does not apply retroactively to contracts formed before it took effect in 2000. Nevertheless, the statute of frauds was satisfied by the text of E-mails plus an (apparently) written notation.)
Sea-Land Service, Inc. v. Lozen International, 285 F.3d 808 (9th Cir., 2002) http://www.admiraltylawguide.com/circt/9thsealandlozen.pdf (Internal corporate E-mail with signature block, forwarded to a third party by another employee, was admissible over hearsay objection as a party-admission, where the statement was apparently within the scope of the author's and forwarder's employment.)