Digital signatures can provide the added assurances of evidence of origin, identity, and status of an electronic document, transaction or message and can acknowledge informed consent by the signer. Digital signatures securely associate a signer with a document in a recorded transaction.
What Is a Digital Signature?
Digital Signature is a process that guarantees that the contents of a message have not been altered in transit. Digital signatures use a standard, accepted format, called Public Key Infrastructure (PKI), to provide the highest levels of security and universal acceptance.
When you -the server- digitally sign a document, you add a one-way hash (encryption) of the message content using your public and private key pair. Your client can still read it, but the process creates a “signature” that only the server’s public key can decrypt. The client, using the server’s public key, can then validate the sender as well as the integrity of message contents.
How do I create a digital signature?
eSignature providers, such as DocuSign, that offer solutions based on digital signature technology, make it easy to digitally sign documents. They provide an interface for sending and signing documents online and work with the appropriate Certificate Authorities to provide trusted digital certificates.
When you receive a document for signing via email, you must authenticate as per the Certificate Authority’s requirements and then “sign” the document by filling out a form online. you may be required to supply specific information. There also may be restrictions and limitations on whom you send documents to for signing and the order in which you send them.
Also, you can obtain a digital signature from a reputable certificate authority such as Comodo, or you can create it yourself. You need a digital certificate to digitally sign a document. However, if you create and use a self-signed certificate the recipients of your documents will not be able to verify the authenticity of your digital signature. They will have to manually trust your self-signed certificate.
if you want the recipients of your documents to be able to verify the authenticity of your digital signature then you must obtain a digital certificate from a reputable CA. After downloading and installing the certificate – you will be able to use the ‘Sign’ and ‘Encrypt’ buttons on your mail client to encrypt and digitally sign your emails. This makes more sense in a business scenario, as it assures the recipient that it was genuinely sent by you and not by some impersonator.
Types of Digital Signatures
Different document processing platforms support and allow the creation of different types of digital signatures.
1- Certified Signatures
Adding a certifying signature to a PDF document indicates that you are the author of the document and want to secure the document against tampering.
Certified PDF documents display a unique blue ribbon across the top of the document. It contains the name of the document signer and the certificate issuer to indicate the authorship and authenticity of the document.
2- Approval Signatures
Approval signatures on a document can be used in your organization’s business workflow. They help optimize your organization’s approval procedure. The process involves capturing approvals made by you and other individuals and embedding them within the PDF document.
Adobe allows signatures to include details such as an image of your physical signature, date, location, and official seal.
3- Visible Digital Signatures
These allow a single user or multiple users to digitally sign a single document. The signatures would appear on the document in the same way as signatures are applied on a physical document.
4- Invisible Digital Signatures
Documents with invisible digital signatures carry a visual indication of a blue ribbon in the taskbar. You can use invisible digital signatures when you do not have to or do not want to display your signature, but you need to provide indications of the authenticity of the document, its integrity, and its origin.
So, Adobe supports certified and approval of digital signatures, But, Microsoft Word supports visible and non-visible digital signatures.