The provider could use digital signatures and secure service tokens (such as X509 certificates) that they have issued to validate the requestor's entitlements.

服务提供者可以使用数字签名和安全服务令牌符号（例如 X509 证书），用它们来验证请求者的权利。

youdao

Secure Multipurpose Internet Mail Extensions (S/MIME) allows digital signatures to be attached to e-mail messages, such that the recipient can verify the identity of the signer.

安全多用途 Internet 邮件扩展（Secure Multipurpose Internet Mail Extensions，S/MIME）允许将数字签名附加到电子邮件消息上，这样接收方就可以验证签名者的身份。

youdao

A link to sample code illustrating a Web service that combines document generation and secure digital signatures in an example workflow is provided below.

下面提供了样例代码的链接，该代码阐述了将文档生成和样例流程中安全的数字签名相结合的Web服务。

youdao

Although Calaceto declined to disclose how much Chase invested in its PKI, he says the costs have decreased dramatically since the bank started researching secure signatures in 1996.

CNN: Technology - E-Signature Act may drive demand for authentication technology

And thanks to work out of Georgia Tech, tactile sensitivity for robotics, more secure e-signatures and general human-machine interaction is about to get a great 'ol boost.

ENGADGET

Despite Mr Sarkozy's tough talk on crime and immigration, the far-right Jean-Marie Le Pen remains a threat (although he has yet to secure the 500 signatures needed to appear on the ballot paper).

ECONOMIST: French politics