AssinaD - Assinatura Digital n

The digital certificate in the ICP-Brasil standard is equivalent to a digital identity, which allows the unequivocal identification of the natural or legal person who signs a digital document. Documents signed with ICP-Brasil digital certificates have legal validity equivalent to a document signed on paper (ITI, 2020b).

The validation of the signature of a digital document using a digital certificate in the ICP-Brasil standard occurs through a third entity of trust, that is, a Certification Authority (CA), which associates an individual or legal entity with the digital certificate when identifying data of the holder according to the Certification Policy (CA) Security Policy (ITI, 2020a).

Certification Authorities (ACs) are subordinate to the National Institute of Information Technology (ITI), which is a federal authority that maintains and executes the Brazilian Public Key Infrastructure (ICP-Brasil) policies, and was initiated by Provisional Measure 2,200- 2 of August 24, 2001 (ITI, 2020b).

The signing of documents using ICP-Brasil digital certificates takes place on the android smartphone device, both when importing ICP-Brasil digital certificates and when signing documents, without the transmission over the internet of the ICP-Brasil digital certificate and the password of the ICP digital certificate. -Brazil.

When signing documents, the internet network is used to validate whether the public key of the digital certificate was signed or revoked by a Certification Authority (CA) that is part of the ICP-Brasil certification chain.

The storage of the ICP-Brasil digital certificate is done in a confidential manner "that other apps cannot access" (DEVELOPERS ANDROID, 2020b). And when uninstalling the app, ICP-Brasil digital certificates are also removed from the “app-specific storage” (DEVELOPERS ANDROID, 2020a).


The application has the following features:

- import of digital certificates (e-CPF and / or e-CNPJ) in computer or mobile formats;

- signing of documents in .pdf, .jpg, .png format;

- removal of ICP-Brasil digital certificates from the application;

- sending or sharing a digital signature file (.p7s file);

- the validation of the digital signature is done on the Conformity Checker on the website of the National Institute of Information Technology at the following link:
https://verificador.iti.gov.br/verifier-2.5.2/

The source code of the application is available from the following link:
https://github.com/assinad/assinad

REFERENCES

ANDROID DEVELOPERS. Access application-specific files. 2020a. Available at: https://developer.android.com/training/data-storage. Accessed on: 07 Aug. 2020.

____________________________. Overview of data and file storage. 2020b. Available at: https://developer.android.com/training/data-storage. Accessed on: 07 Aug. 2020.

ITI. Digital certificate. 2020a. Available at: https://iti.gov.br/institucional/43-institucional/89-o-iti. Accessed on: 06 Aug. 2020.

___. ITI. 2020b. Available at: http://www.iti.gov.br/institucional/o-iti. Accessed on: 06 Aug. 2020.

App icon by Freepik at https://www.flaticon.com/free-icon/signature_985371?term=signature&page=1&position=18