1. All appeals filed by the Plaintiff and Defendant C are dismissed.

2. Of the appeal costs, the part arising between the Plaintiff and the Defendant C.

1. Basic facts

A. On February 23, 2012, E, a substantial operator of A (hereinafter “A”) concluded a performance guarantee insurance contract (hereinafter “instant insurance contract”) with the Plaintiff operating the insurance business and A, setting the insurance coverage amount as “40 million won”, “the partnership agreement of the insured corporation”, “from February 23, 2012 to February 26, 2013”, “the insurance coverage period as “from February 23, 2012 to February 26, 2013”, and “the payment guarantee for the sales of foreign goods” as “the payment guarantee for the foreign goods”).

B. After that, the insured corporation, the insured, did not perform the obligation under the main contract (the payment of the sales price for goods out of the market) and on June 7, 2013, the Plaintiff notified the Plaintiff of the occurrence of the insurance accident and claimed the payment of the insurance money, and on July 12, 2013, the Plaintiff paid KRW 39,596,188 of the insurance money to Dong Branch Co., Ltd.

C. Meanwhile, the instant insurance contract was concluded by electronic contract through digital signature, and the Defendants respectively concluded a joint and several guarantee agreement for the obligation to be borne by A under the instant insurance contract through digital signature using an authorized certificate.

[Ground of recognition] Facts without dispute, Gap evidence Nos. 1, 2, 3, 5, 6, 9, 10 (if any, including each number; hereinafter the same shall apply), the purport of the whole pleadings

2. Determination as to the claim against Defendant C

A. Article 3(2) of the Digital Signature Act provides that “where a certified digital signature exists, the relevant digital signature shall be signed, sealed, or sealed by the Signatory, and its content shall be presumed not to have been altered after the digital signature was affixed.” Article 18-2 of the same Act provides that “where other Acts restrict or exclude the verification of the person himself/herself by using an authorized certificate, he/she may verify his/her identity by using an authorized certificate issued by a licensed certification authority in accordance with the provisions of this Act, and Article 358 of the Civil Procedure Act shall also apply.”