According to the Code of Federal Regulation, electronic signatures are defined as a computer data compilation of any symbol or series of symbols executed, adopted, or authorized by an individual to be the legally binding equivalent of the individual's handwritten signature. A specific type of electronic signature is digital signatures. Digital signatures are defined as an electronic signature based upon cryptographic methods of originator authentication, computed by using a set of rules and a set of parameters such that the identity of the signer and the integrity of the data can be verified.
An entity such as a computer user can be assigned a unique digital identification. This digital identification is composed of a public key, a private key, and a digital certificate. As their names suggest, the public key should be shared amongst users who wish to carry out transactions amongst themselves, while the private key should be only known by its user. The digital certificate is used within a public-key infrastructure to allow a third-party certificate authority to verify that the digital certificate is correctly associated with that particular public key.
As public keys are shared amongst a group of users, someone’s public key can be used to encrypt a document and their respective private key can be used to decrypt that document. Confidentiality and data integrity of the sent document can be practically guaranteed assuming if the recipient is the only one who knows their private key. Similarly, someone’s private key can be ‘embedded’ into a document to constitute an electronic signature, and the identity of the electronic signature may be verified by using that user’s public key.
The Michigan Attorney General’s office, in concurrence of the Federal Highway Administration, has issued a decision authorizing the Michigan Department of Transportation (MDOT) to use and accept digital signatures (see BOH IM 2012-02).
There are many standards available for digital signatures, but MDOT currently authorizes the use of PKCS#12 files for digital identification. This cryptographic standard requires the signer to enter their unique password each time they digitally sign a document. To digitally sign a document, you must first have a digital identification (ID). This ID can be obtained from various certification authorities, but MDOT will primarily use Adobe as a certification authority. This PDF file and this YouTube video shows how to create a digital ID on Adobe Reader.
Digital signatures created with Adobe Software need to conform to the following style guidelines:
- Graphic options shall be:
- “Name” Or “Imported Graphic” (as outlined below)
- Configure text shall be configured as:
- Uncheck the adobe “logo”
- Required to include: (“Name”, “Date”, “Location” and “Reason”)
- Optional “Distinguished Name” (includes job title)
- Optional for “labels”
- “left to right”
You may have multiple digital signature files configured for different purposes. It is even possible to configure a digital signature with an “Imported Graphic” (refer to this PDF) containing an image of your scanned written signature or a scan of a professional license stamp. These are acceptable, but written signature images are not required and non-business related graphics are not acceptable.
Similar to how handwritten signatures must be verified, it is the responsibility of the recipient of a electronically signed document to confirm the identity of the signer/sender before the electronic signature may be considered valid. The recipient should consider whether or not that the document was sent from a recognized e-mail account and that the expected signer has been previously validated. If you are unsure, then you can verify by contacting their place of business. Adobe Acrobat software has an integrated validation feature that stores validated signatures, meaning that the user does not need to validate those signatures again. This PDF shows how to validate a signature.
MDOT is working on integration of electronic signatures on mobile devices. There are several mobile applications that allow PDF files to be digitally signed using mobile devices, but as of now none have been authorized for employee use. Employees are encouraged to submit mobile applications to the E-Sign team of the Construction Field Services Division and to the Department of Technology, Management and Budget. This PDF shows how to digitally sign a PDF file on an iPhone.
It is important to note that for records retention and archiving purposes whenever digital signatures are used on documents, the electronic file (usually PDF) is considered the original legal document. Printouts of the document containing digital signatures are considered copies, so the signed electronic file must be retained and follow the relevant approved records retention procedures. MDOT will address the records storage issue through the requirement that all electronically signed documents must be placed in the project directory in the ProjectWise document management program. The E-construction wiki page contains more information regarding ProjectWise.