Save Digital Signature Validated with airSlate SignNow

Digital signature terms of use agreement

hey there so today we're going to talk about digital signatures I think there's a lot of confusion when it comes to digital signatures or electronic signatures so we're gonna kind of straighten that out and get that a little bit clearer and then I'll walk through an example of how digital signatures get used so I think this will be an interesting video if if this is a topic that interests you by all means keep on watching so first off in life you know we have to sign documents we gotta sign contracts we gotta sign agreements it's just you know how life goes so you know traditionally we would take a pen and paper right and we would actually sign on a piece of paper and this is in the business this is called a wet signature I don't know why they call it a wet signature because ink is wet anyways so that's what signature now we can take that signature and we could scan it for example into an image and then insert that image into a document that's usually referred to as a digitized signature and that may or may not be legally binding organizations use it all the time though can also be abused so you got to be careful with it but but that's not really what an electronic signature is an electronic signature or an e signature is a means of obtaining a legal signature on an electronic document and this happens in a lot of different ways think of it when you install software on a computer you see that long end user License Agreement you scroll through don't read any of it and just click agree or click Next well that's a form of an e-signature right you're you're agreeing to the terms of service when the courier lady comes and you have to sign for your package she holds out the pad and you gotta you gotta sign well that's a form of an electronic signature as well you're physically signing the electronic pad you're there capturing an electronic signature from you and of course there are services also that offer you know digital signatures on documents you've probably heard of like DocuSign certainly Adobe provides this kind of service as well and functionality like this for Acrobat so you know that's that's sort of the distinction between all of them now a digital signature is a form of an electronic signature but it's a little bit different in that it uses public key cryptography and asymmetric keys to provide authenticity integrity and non-repudiation and I'll talk about what those are in just a minute now because it uses public key cryptography that means it uses digital certificates so you have to have a trusted certificate authority that's going to assign the certificate and that could be internal to an organization but more often than not it's going to be a public CA so that's where you see the the digit cert or the comodo or the GeoTrust certificates being used and because it uses asymmetric cryptography asymmetric keys we got to have that public private key pair already generated and the public key available and we'll talk a little bit more about about that as well a little bit now it's important to know that digital signatures can be applied to any kind of digital item it can be we mostly think of it as you know signing an email or signing documents or PDF files but it could be you know any kind of file videos pictures audio files and increasingly we see the software we see executables being signed we see signed digital drivers so so digital signatures are very powerful and they're used all over the place now a digital signature is a hash value that's encrypted with the sender's private key all right so let's break that down a little bit a hash value we talked about hashes a few videos ago but a hash is basically a one-way cryptographic function it creates a fixed size unique fingerprint of some data it's used to provide integrity which means we can make sure that whatever that data is hasn't been changed because if we change even one bit of that data the hash value will change dramatically so that's where we get the integrity from now hash value encrypted with the sender's private key so in asymmetric cryptography there are two keys and whatever one key does the other key undoes so we commonly call this a public key and a private key the public key is public anybody can have it but the private key you got to keep secure you got to keep it to yourself only you get the private key so when only you have that key it provides authenticity because only you have that key but it also provides non-repudiation because and our repudiation is the ability to deny something right you can't deny having done something so if I'm signing something and I'm using my private key to do it only I have the private key and therefore only I could have signed it I can't say that I didn't write that's what non repudiation is all about anyways so that's that's really what a digital signature is it's a hash value that gets encrypted with the sender's private key so let's talk about creating a digital signature and I'm going to describe these in sort of manual steps but it doesn't they're not really quite this manual it's more behind the scenes that things happen you know your mail client probably has the ability to create signed email messages you don't have to like copy the email message to a file and then LUT command line goes like not all that this is often built-in this is these stops just illustrating how a digital and a digital signature really works so creating a digital signature like I said we're going to generate a hash value of the data which is what gives us the integrity we're going to encrypt that hash value with the private key which gives us the authenticity and non-repudiation and then I can take my data the signature and potentially the public key that I have maybe it's in a certificate and I can send that all to you and with that you can now validate that that informality that information so on the validation side you're going to generate the hash of the data using the same hashing algorithm that I use you're going to verify that my public key is still valid and if I send it to you you'll obviously be able to see that in the certificate or if you got it from a from a key server you'd be able to see it there as well and then you can decrypt the the digital signature using like public key and then you'll compare the two hash values and if the hash values are the same then you know nothing's changed and everything is good that's that's really about it right that's that's how they work that's simple but is very powerful now you may have noticed that when I described all of this we haven't at all talked about confidentiality or encryption so digital signatures don't provide any type of encryption or confidentiality if that's required we're gonna have to do something else to encrypt our our message or our data to provide that but a digital signature all this doing has given us that authenticity integrity and non-repudiation and that's it yeah so if you write an exam it's it's not complicated to remember this but you kind of might have to step through the process in your head a little bit or at least I do to keep it straight anyways that's it digital signatures have yourself a great weekend take care