Pierluigi Paganini
May 13, 2012
Private companies and governments agencies all around the word make huge investments for the automation of their processes and in the management of the electronic documentation.
The main requirement in the management of digital documentation is its equivalence, from a legal perspective, to paperwork, affixing a signature on a digital document is the fundamental principle on which are based the main processes of authorization and validation, apart from the specific area of application.
Main benefits for the introduction of digital signing processes are cost reduction and complete automation of documental workflow, including authorization and validation phases.
In essence, digital signatures allow you to replace the approval process on paper, slow and expensive, with a fully digital system, faster and cheaper.
Figura 1 – Digital document lifecycle
The digital signature is simply a procedure which guarantees the authenticity and integrity of messages and documents exchanged and stored with computer tools, just as in traditional handwritten signature for documents. Essentially The digital signature of an electronic document aims to fulfill the following requirements:
A typical digital signature scheme consists of three algorithms:
To generate a digital signature is necessary to use the digital asymmetric key pair, attributed unequivocally to a person, called holder of the key pair:
Once the document is signed with the private key, the signature can be verified successfully only with the corresponding public key. Security is guaranteed by the impossibility to reconstruct the private key (secret) from the public, even if the two keys are uniquely connected.
A Digital signature is a one-way hash, of the original data, that has been encrypted with the signer’s private key. A digital signature process is composed by the following steps:
For the verification, The receiving software first uses the signer’s public key to decrypt the hash, then it uses the same hashing algorithm that generated the original hash to generate a new one-way hash of the same data. The receiving software compares the new hash against the original hash. If the two hashes match, the data has not changed since it was signed.
Figura 2 – Digital Signature Process
The authenticity of a document can be verified by anyone decrypting the signature of the document with the sender’s public key, obtaining the fingerprint of the document, then comparing it with that obtained by applying the hash function (which is known) to the document received which was attached the signature. If the two fingerprints are equal, the authenticity and integrity of the document are demonstrated.
The signing and verification operations may be delegated to a schedule issued by the certification.
Thanks to the mechanism shown, the digital signature ensures non-repudiation: the signer of a document transmitted cannot deny having sent it and the receiver can deny to have received it. In other words means that the information cannot be ignored, as in the case of a conventional signature on a paper document in the presence of witnesses.
The advantages of digital signatures
The activation of a fully automated workflow, digital signatures, reduce time and costs associated with the signatures on paper, the latter in fact have an economic cost and create delays and inefficiencies.
An estimate provided by ARX on the basis of current data sets that each of their clients handwritten signature on a paper document to determine the company at a cost of $ 30 U.S including costs associated with paper, printing costs, of signing, scanning, forwarding, storage and regeneration of lost or missing documents. According to the study of ARX, a person authorized to sign documents marking more than 500 documents a year.
The digital signatures process is essential for the formal approval processes of every companies, a typical scenario require multiple authorization of multiple offices for each document.
Thus digital signatures allow alternate approval processes, collaboration and delivery of paper (expensive and slow), with a digital system (faster, cheaper and more efficient).This results in a number of advantages:
Resuming, digital signatures can reliably automate the signatures of authorization allowing the elimination of paper, reducing costs and improving the speed of production processes.
By virtue of all these advantages, the digital signature can be particularly useful for:
Pierluigi Paganini
