What is a digital signature?

Digital signatures are like electronic fingerprints for documents: A digital signature securely associates a signer with a document. Digital signatures use a standard, accepted format — called a public key infrastructure (PKI) — to provide the highest levels of security and universal acceptance. A PKI involves using a digital certificate from a certificate authority (CA) for identity verification.

What is a digital certificate?

A digital certificate is issued by a certificate authority (CA). It contains the public key for a digital signature and specifies the identity associated with the key, such as the name of an organization. The certificate is used to confirm that the public key belongs to the organization, and the CA acts as the guarantor. Digital certificates must be issued by a trusted authority and are only valid for a specified time. They’re necessary to create a digital signature in a document.

What's the difference between electronic and digital signatures?

An electronic signature is a visual representation of a signature, similar to a handwritten signature on a printed document. It states who signed a document, acts as an acknowledgement, and could represent an agreement or contract. Digital signatures, on the other hand, create a unique digital fingerprint of a document using cryptographic technology, providing enhanced security and verifying the integrity of the document’s contents. When using an electronic signature, one can acknowledge accepted terms to a contract by adding a visual signature. When using a digital signature, one can be assured the document's content has not been tampered with, as it verifies the digital signer's identity.

What are the system requirements for integrating the Digital Signatures SDK into a web application?

To digitally sign a document, you must obtain a certificate from a trusted certificate authority (CA). Adobe provides a list of trusted certificate authorities to be used when signing documents: https://helpx.adobe.com/acrobat/kb/approved-trust-list1.html

Is there a trial version of the Digital Signatures SDK?

Our SDKs offer a flexible trial experience. You have the option to try our SDK with or without obtaining a trial key. The no trial key option is perfect for developers who want a quick look at all of an SDK's capabilities. However, it's important to note that this method comes with certain limitations: A red watermark will appear at the top of each page when viewing documents. If any alterations are made to a document, such as adding annotations, the red watermark will become a permanent fixture of the edited file. After running the app for one hour after a document is loaded, the viewer will show an alert. By obtaining a 30-day trial key, you'll unlock the SDK's full capabilities for 30 days without any of the aforementioned limitations.

What kind of support does PSPDFKit offer for digital signatures?

PSPDFKit can create and validate digital signatures for PDF documents using the `adobe.pkcs7.detached` method, and it supports the RSA and ECDSA signing algorithms, along with multiple hashing options, including the MD4, MD5, and SHA-2 variants.