| DocumentSignatureInfo | Contains information about signatures of a document. |
| BiometricSignatureData | Biometric data of a Signature. |
| BiometricSignatureData.Builder | Builder for BiometricSignatureData. |
| DigitalSignatureInfo | A digital signature stored inside a PDF document. |
| DigitalSignatureInfo.BuildData | Build data dictionary of a software that created the digital signature. |
| DigitalSignatureInfo.Reference | Signature reference dictionary. |
| DigitalSignatureValidationResult | Detailed status about validity of a DigitalSignatureInfo. |
| DigitalSignatureValidator | Validates digital signatures. |
| Signature | Represents a single signature (or signature item). |
| SignatureAppearance | Configures the appearance of digital signatures that are added to the document. |
| SignatureAppearance.Builder | A helper class used for building the SignatureAppearance. |
| SignatureAppearance.SignatureGraphic | Contains the graphic that will be used as the signature. |
| SignatureManager | Handles digital signature certificates. |
| SignatureMetadata | Additional metadata that can be added to digital signatures. |
| SignatureMetadata.Builder | A helper class used for building the SignatureMetadata. |
| BiometricSignatureData.InputMethod | Types of input devices that for creating a signature. |
| DigitalSignatureInfo.ReferenceTransformMethod | List of possible transformation methods of a DigitalSignatureInfo.Reference. |
| DigitalSignatureValidationResult.CertificateStatus | Status of the certificate that was used for signing the document. |
| DigitalSignatureValidationResult.DocumentIntegrityStatus | Status of the signed document. |
| DigitalSignatureValidationResult.ValidationProblem | Problems that prevented proper validation of a signature. |
| EncryptionAlgorithm | Encryption algorithm used for digitally signing a PDF. |
| FilterSubtype | A filter sub type refers to an encoding or format that was used to create the signature. |
| HashAlgorithm | Hash algorithm for digesting PDF data as part of a digital signing process. |
| SignatureAppearance.SignatureAppearanceMode | Controls how the digital signature will appear after signing. |
| SigningStatus | Result of signing operation. |
| ValidationStatus | Represents overall validation status. |
| SigningFailedException | Thrown by Signer when signing of a document failed. |