When a signature line is inserted into an Office file, the author can specify information about the intended signer, and instructions for the signer. Top of Page Signature lines in Word and ExcelДЄ signature line resembles a typical signature placeholder that might appear in a printed document. The certificate associated with the digital signature is issued to the signing publisher by a reputable certificate authority (CA). Important:В Signed documents, which have a valid time stamp, are considered to have valid signatures, regardless of the age, or revocation status, of the signing certificate. The signing person or organization, known as the publisher, is trusted. The certificate associated with the digital signature is current (not expired).

To make these assurances, the content creator must digitally sign the content by using a signature that satisfies the following criteria: Notarization Signatures in Word, Excel, or PowerPoint files, which are time stamped by a secure time-stamp server, under certain circumstances, have the validity of a notarization. Repudiation refers to the act of a signer denying any association with the signed content. Non-repudiation Proves to all parties the origin of the signed content. Integrity The content has not been changed or tampered with since it was digitally signed. Digital signature assurancesДЄuthenticity The signer is confirmed as the signer. It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired. Note:В You can learn more about public and private keys in this article.Д¬ertificate authority (CA) A certificate authority is an entity similar to a notary public. A certificate is usually valid for a year, after which, the signer must renew, or get a new, a signing certificate to establish identity. Certificates are issued by a certification authority, and like a driver's license, can be revoked. When you send a digitally-signed macro or document, you also send your certificate and public key. Signing certificate To create a digital signature, you have to have a signing certificate, which proves identity. Signing certificate and certificate authority A signature confirms that the information originated from the signer and has not been altered. Next to the signature name, click the arrow.ДЄ digital signature is an electronic, encrypted, stamp of authentication on digital information such as e-mail messages, macros, or electronic documents. The document, worksheet, or presentation view returns, and the Signatures pane appears. Open the document, worksheet, or presentation that contains the invisible signature you want to remove. Top of Page Remove invisible digital signatures from Word, Excel, or PowerPoint In the Sign dialog box, in the Purpose for signing this document box, type the purpose.ДЄfter a file is digitally signed, the Signatures button appears, and the file becomes read-only to prevent modifications. Read the Word, Excel, or PowerPoint message, and then click OK. Signed documents have the Signatures button at the bottom of the document.Д¬lick Protect Document, Protect Workbook or Protect Presentation. To protect the authenticity of a document's content, you can add an invisible digital signature. Top of Page Add invisible digital signatures in Word, Excel, or PowerPoint Note:В In addition, you can remove a signature by clicking the arrow next to the signature in the Signature Pane. Show sign date in signature line Signature date will appear with signature. Select one or both of the following check boxes:ДЄllow the signer to add comments in the Sign dialog box Allow the signer to type a purpose for signing. Instructions to the signer Add instructions for the signer. Suggested signer's e-mail address The signer's e-mail address, if needed. Suggested signer's title The signer's title, if any. In the Signature Setup dialog box, type information that will appear beneath the signature line: On the Insert tab, in the Text group, click the Signature Line list, and then click Microsoft Office Signature Line. In the document or worksheet, place your pointer where you want to create a signature line. Invisible digital signatures in Word, Excel, or PowerPoint Create a signature line in Word or Excel Remove invisible digital signatures from Word, Excel, or PowerPoint Remove digital signatures from Word or ExcelДЄdd invisible digital signatures in Word, Excel, or PowerPoint This article explains digital signatures (also known as digital ID), what they can be used for, and how you can use digital signatures in the following Microsoft Office programs: Word, Excel, and PowerPoint.

Create a digital signature in excel