實(shi)踐中(zhong)，通過電子簽(qian)名方式簽(qian)署(shu)電子合同，一般需要有四方介入：

• 電(dian)子合同服(fu)務平臺

• 簽(qian)訂合同的主體(ti)

• 電子認證服務機構

• 可信第三方時間戳服務中心

通過主體認(ren)證、加密認(ren)證、加蓋(gai)時間(jian)戳(chuo)，生成加蓋(gai)電(dian)子(zi)簽名(ming)的電(dian)子(zi)合(he)同(tong)。《電(dian)子(zi)簽名(ming)法(fa)》規定：“當事(shi)人(ren)約定使用(yong)電子簽名、數據電文(wen)(wen)(wen)的(de)文(wen)(wen)(wen)書，不(bu)得僅因為其采用(yong)電子簽名、數據電文(wen)(wen)(wen)的(de)形式而否定其法律效力。”

劉芳(fang)表示，目前(qian)法院比較傾(qing)向采(cai)納的是當(dang)事人是否(fou)同意以電(dian)子手(shou)段進行交(jiao)易，由(you)上下文和周圍(wei)情勢，包括當(dang)事人的行為(wei)來確(que)定(ding)。實踐中，當(dang)事人應盡量避(bi)免發生上述爭(zheng)議，爭(zheng)取在協議中明確(que)約定(ding)使(shi)用(yong)或(huo)者不使(shi)用(yong)電(dian)子簽名(ming)。

劉芳指出，可(ke)靠電子簽名必須具備以下四個要素：

• 電子(zi)(zi)(zi)簽名制作數據(ju)用于電子(zi)(zi)(zi)簽名時(shi)，屬于電子(zi)(zi)(zi)簽名人專有；

• 簽署時電子(zi)簽名制(zhi)作數據僅由電子(zi)簽名人(ren)控制(zhi)；

• 簽署后(hou)對電子簽名的任(ren)何改(gai)動(dong)能(neng)夠被發現(xian)；

• 簽署后對數據電文內(nei)容和形(xing)式的任何改(gai)動能(neng)夠被發現(xian)。

此外，作為證(zheng)據(ju)的(de)(de)(de)一(yi)種，電子證(zheng)據(ju)應具備(bei)證(zheng)據(ju)的(de)(de)(de)通常屬性(xing)(xing)(xing)(xing)(xing)：客觀性(xing)(xing)(xing)(xing)(xing)，關聯性(xing)(xing)(xing)(xing)(xing)和(he)合法(fa)性(xing)(xing)(xing)(xing)(xing)。劉芳強調，與其(qi)它證(zheng)據(ju)不同的(de)(de)(de)是，電子證(zheng)據(ju)的(de)(de)(de)證(zheng)明能力(li)需要通過特定(ding)技術處理，把(ba)數(shu)字編(bian)碼轉化成可(ke)(ke)(ke)感(gan)知的(de)(de)(de)視聽材料(liao)來實(shi)(shi)(shi)現，這涉及數(shu)據(ju)電文(wen)(wen)(wen)的(de)(de)(de)證(zheng)實(shi)(shi)(shi)性(xing)(xing)(xing)(xing)(xing)問題(ti)。根據(ju)規定(ding)，審查數(shu)據(ju)電文(wen)(wen)(wen)作為證(zheng)據(ju)的(de)(de)(de)真實(shi)(shi)(shi)性(xing)(xing)(xing)(xing)(xing)，應考慮以(yi)下因素：生成、儲存或者傳遞數(shu)據(ju)電文(wen)(wen)(wen)方法(fa)的(de)(de)(de)可(ke)(ke)(ke)靠(kao)性(xing)(xing)(xing)(xing)(xing)；保(bao)持內(nei)容完(wan)整性(xing)(xing)(xing)(xing)(xing)方法(fa)的(de)(de)(de)可(ke)(ke)(ke)靠(kao)性(xing)(xing)(xing)(xing)(xing)；用以(yi)鑒別發(fa)件人方法(fa)的(de)(de)(de)可(ke)(ke)(ke)靠(kao)性(xing)(xing)(xing)(xing)(xing)；其(qi)他相關因素。

世澤律師事務所合伙人袁星對電(dian)(dian)(dian)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)的法律效(xiao)(xiao)力、數(shu)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)技(ji)(ji)術(shu)(shu)及功能，以及電(dian)(dian)(dian)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)司(si)法實(shi)踐(jian)進行總結(jie)。他表示，可(ke)靠(kao)(kao)電(dian)(dian)(dian)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)具有與(yu)手寫簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)或者(zhe)蓋章同等的法律效(xiao)(xiao)力，可(ke)靠(kao)(kao)電(dian)(dian)(dian)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)可(ke)用(yong)于證(zheng)明電(dian)(dian)(dian)子(zi)方式簽(qian)(qian)(qian)(qian)署合同（數(shu)據(ju)電(dian)(dian)(dian)文）的真實(shi)性(xing)(xing)(xing)；電(dian)(dian)(dian)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)有多種技(ji)(ji)術(shu)(shu)選擇，數(shu)據(ju)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)技(ji)(ji)術(shu)(shu)主要(yao)(yao)涉及非對稱加密技(ji)(ji)術(shu)(shu)、哈希摘要(yao)(yao)技(ji)(ji)術(shu)(shu)和時間戳(chuo)技(ji)(ji)術(shu)(shu)。數(shu)據(ju)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)技(ji)(ji)術(shu)(shu)主要(yao)(yao)參與(yu)方為(wei)數(shu)據(ju)發出(chu)人、接收人、CA認(ren)(ren)(ren)證(zheng)機構(gou)、可(ke)信(xin)時間戳(chuo)機構(gou)；數(shu)據(ju)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)技(ji)(ji)術(shu)(shu)可(ke)以解決可(ke)靠(kao)(kao)電(dian)(dian)(dian)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)的兩個(ge)問題(ti)：確(que)認(ren)(ren)(ren)數(shu)據(ju)電(dian)(dian)(dian)文簽(qian)(qian)(qian)(qian)發人的身份，確(que)認(ren)(ren)(ren)數(shu)據(ju)電(dian)(dian)(dian)文未(wei)經過篡改(gai)。司(si)法實(shi)踐(jian)中，電(dian)(dian)(dian)子(zi)合同效(xiao)(xiao)力已被廣泛認(ren)(ren)(ren)可(ke)，通常由第三(san)方電(dian)(dian)(dian)子(zi)簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)服務平臺出(chu)具《真實(shi)性(xing)(xing)(xing)報告》或由CA認(ren)(ren)(ren)證(zheng)中心出(chu)具《數(shu)字簽(qian)(qian)(qian)(qian)名(ming)(ming)(ming)(ming)認(ren)(ren)(ren)證(zheng)報告》等方式證(zheng)明電(dian)(dian)(dian)子(zi)合同的真實(shi)性(xing)(xing)(xing)。