SHA-1 Digital Signatures

Exacta uses signature dynamic technology to authenticate our surveying and mapping work product as well as other documents electronically transmitted via STARS. Exacta’s digital authentication process generates a SHA-1 Hash code that is capable of verification by our clients and other intended users of our PDF work product. This SHA-1 Hash code is unique to each of our licensed professionals and its use is under their sole control.

Each SHA-1 Hash code consists of 40 characters unique to the electronically transmitted PDF work product and the licensed professional whose signature and seal appears on them. Delivered at the same time as our PDF work product is a separate invoice document containing a 40 character SHA-1 Hash code that is created for and associated with that specific work product. Exacta maintains all records associated with our SHA-1 Hash code for our work product and therefore can be retrieved by logging into STARS or contacting us directly.
To authenticate Exacta’s PDF work product; simply copy the PDF into any of the many available SHA-1 Hash authentication programs available online or visit The Online MD5 and use the authentication program provided there. If the 40 character codes are exactly the same, then you know that the PDF document in your possession is properly signed and the work product is authentic.

In the event, the SHA-1 Hash code that is emitted by using an authentication program is ever different, this means that somewhere along the way, the information contained on that PDF work product was altered; therefore, it would no longer be valid. In the end, any authenticated electronically signed PDF that you receive is far more secure than any paper document.

However, in certain jurisdictions the local permitting office or building department, for any number of reasons, may require a raised seal copy of the work product. In those circumstances our licensed professional surveyor will be happy to print, crimp and mail a raised seal copy(s) for these purposes.