隨著文檔自動化和電子簽名平台在法律界日益興起，法律交易日趨無紙化，企業需要了解電子簽名的影響和執行力，同時也需要謹慎行事。電子簽名無疑能提高效率，但對於電子簽名涉及的數據安全（電子 簽名平台基於雲服務）和欺詐風險、電子簽名是否符合相關法規/審計要求，以及簽名是否為真實意思表示等，仍然存在擔憂。
電子簽名的多種形式
「電子簽名」可以有多種形式，包括：
• 在電子文檔中隨附 pdf 或 jpeg 格式的手寫簽名；
• 在包含合同/協議條款的電子郵件中輸入姓名；
• 勾選載明「本人接受」協議條款（或其他類似措辭）的方框；
• 電子簽名平台生成的簽名，即在電子文檔上通過勾選方框或輸入姓名，生 成電子簽名（該電子簽名可能與簽字人手寫簽名並不必然相似）；以及
• 在「簽字屏」上用輸入筆簽名或親手簽名，在螢幕顯示的電子文檔上生成 和簽名人的手寫簽名近似的簽名。
新加坡電子簽名法ETA規定，如果一項法律規則要求籤名，或規定某一文件未經簽名會產生特定的法律後果，則採用電子簽名的形式滿足該法律規則。同時該法又規定，通過使用法定的安全程序，或當事人同意採用的合理安全的商業程序，如果能夠證實一項簽名在製作時符合下列條件，則該簽名可以視為安全的數字簽名：
1．使用者唯一的簽名；
2．能證實使用者的身份；
3．通過某種使用者可以唯一控制的方式或方法創設；
4．和相關的電子記錄以某種方式具有密切聯繫，一旦該記錄被修改，則簽名也隨之失效。
以下文件不包含在ETA中，因此無法進行電子簽名：
遺囑
可轉讓票據，所有權憑證，匯票，期票，寄售票據，提貨單，倉庫收據或任何使持單人或受益人有權要求交付貨物或支付款項的可轉讓文件或票據
契約的創建，信託的聲明，委託書, 永久授權書
任何出售或其他處置不動產的合同，或該不動產的任何權益轉讓
Electronic signatures are commonly used for all types of transactions in Singapore, and their use is increasing as a result of expanded use by local companies. Singaporean law makes a distinction between electronic signatures and secure electronic signatures, with digital signatures backed by certificates from trusted service providers treated as a form of secure electronic signature.
In Singapore, the use of electronic and secure electronic signatures is governed by the Electronic Transactions Act, Cap 88 and the Electronic Transactions (Certification Authority) Regulations 2010. The Personal Data Protection Act 2012 (PDPA) is also relevant to personal information used in secure electronic signatures.
For an electronic signature to be valid, it must meet the following conditions:
There must be reliable assurance about the integrity of information in the electronic record, from the time it was first made in its final form;
Where the electronic record is to be provided to a person, it must be capable of being displayed to that person; and
It must comply with any additional requirements relating to electronic records specified by the public agency supervising the provision or retention of such records.
For a secure electronic signature to be valid, it must be possible to verify that, at the time it was made, it was:
unique to the person using it;
capable of identifying such person;
created in a manner or using a means under the sole control of the person using it; and
linked to the electronic record to which it relates in a manner such that if the record was changed the electronic signature would be invalidated.
The above conditions for a secure electronic signature can be met through the application of a specified security procedure (as prescribed under the Electronic Transactions (Certification Authority) Regulations 2010 as well as the Third Schedule to the ETA), or a commercially reasonable security procedure agreed to by the parties involved.
Under the Electronic Transactions Act, both electronic signatures and secure electronic signatures are enforceable and admissible. However, in proceedings involving a secure electronic signature, the signature will have the same presumption of enforceability as a 「wet signature」. If the electronic signature is not secure, this presumption will not apply.
In addition to the requirements for a valid secure electronic signature, a digital signature must meet the following conditions:
It must have been created during the operational period of a valid certificate and could be verified by reference to the public key listed in that certificate; and
The certificate is considered trustworthy because:
it was issued by an accredited certification authority operating in compliance with the regulations; or
it was issued by a recognized certification authority; or
it was issued by a public agency approved by the Minister to act as a certification authority on such conditions as he may by regulations impose or specify; or
the parties have expressly agreed between themselves (sender and recipient) to use a digital signature as a security procedure, and the digital signature was properly verified by reference to the signatory’s public key.
The ETA includes a voluntary accreditation scheme of CAs, which is overseen by the Infocomm Development Authority of Singapore. However, non-accredited CAs still need to comply with basic duties and obligations, which include the duty to use trustworthy systems in their businesses and to issue, suspend, revoke, and publish its certificates under specific circumstances. Accredited CAs must comply with additional duties and obligations such as undergoing audits prior to each term of accreditation and more stringent requirements relating to the issuance, suspension, revocation, and publication of its certificates.
Digital signatures based on digital certificates issued by accredited CAs are automatically considered to be trustworthy and are recognised by the law.
Judges are familiar with the laws surrounding e-records and e-signatures. Electronic signatures are widely accepted as evidence, and judges frequently cite the ETA in cases pertaining to signatures and contracts.
Special considerations
In Singapore, PDPA states that organizations shall not transfer any personal data they hold to a country or territory outside of Singapore, except in accordance with the requirements prescribed under PDPA.
Use cases that generally require a traditional signature
In Singapore, there are several use cases that generally require a traditional signature. Additionally, there are several instances that require additional consideration for legal compliance of e-signatures such as when transacting with public sector entities. The following are excluded from the ETA and therefore cannot be electronically signed:
Wills
Negotiable instruments, documents of title, bills of exchange, promissory notes, consignment notes, bills of lading, warehouse receipts or any transferable document or instrument that entitles the bearer or beneficiary to claim the delivery of goods or the payment of a sum of money
The creation, performance or enforcement of an indenture, declaration of trust or power of attorney, with the exception of implied, constructive and resulting trust.
Any contract for the sale or other disposition of immovable property, or any interest in such property
The conveyance of immovable property or the transfer of any interest in immovable property
