What is the test for authenticity in a civil case?

While Salcido frames this as an issue of authenticity, this argument is more properly considered a challenge to the sufficiency of the evidence. See United States v. Nolan, 818 F.2d 1015, 1016-17 (1st Cir.1987) ("Whether the pictures were the kind of visual depictions the law forbids, i.e., ones involving the `use' of actual minors engaging in sexually explicit conduct, 18 U.S.C. 2252(a)(2)(A), goes more properly to whether the government presented sufficient evidence to prove all the elements of its case than to `authentication.'"), abrogated on other grounds by United States v. Hilton (Hilton I), 363 F.3d 58 (1st Cir.2004), withdrawn, United States v. Hilton (Hilton II), 386 F.3d 13 (1st Cir.2004).