Solved

Digital signature

Posted on 2014-04-02
11
418 Views
Last Modified: 2014-04-03
What is a digital signature, does it involve a hash.

(Assuming SSL)
0
Comment
Question by:Anthony Lucia
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
11 Comments
 
LVL 23

Expert Comment

by:Patrick Bogers
ID: 39973017
Hi

It means your mail / files are signed by an SSL certificate.
It involves encryption.
0
 
LVL 54

Expert Comment

by:Joe Winograd, EE MVE
ID: 39973045
Hi Dave,
The Wikipedia article about it is helpful:
http://en.wikipedia.org/wiki/Digital_signature

And here's a short article with a brief definition:
http://searchsecurity.techtarget.com/definition/digital-signature

This is different from a bitmap graphic that is used to put an image of your "real" signature on a document, as discussed in this article:
http://www.experts-exchange.com/Software/Photos_Graphics/Images_and_Photos/A_12380-Signature-Image-with-Transparent-Background.html

Regards, Joe
0
 
LVL 6

Expert Comment

by:Biniek
ID: 39973258
You can look into some Microsoft documents online, in my opinion it is presented in an accessible way:

Understanding Digital Certificates
http://technet.microsoft.com/en-us/library/bb123848(v=exchg.65).aspx

Understanding S/MIME
http://technet.microsoft.com/en-us/library/aa995740(v=exchg.65).aspx

Understanding Public Key Cryptography
http://technet.microsoft.com/en-us/library/aa998077(v=exchg.65).aspx

I'd like to recommend to You very good tool - Cryptool - Educational Tool for Cryptography and Cryptanalysis, this is very simple tool, and help You to understand digital signature.
www.cryptool.org - but now the webpage is closed, because they are moving to new serwer
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 33

Accepted Solution

by:
Dave Howe earned 500 total points
ID: 39973630
Most cryptographic signatures are in fact the hash of the message encrypted with the signer's private asymmetric key. By decrypting the key using the matching public key, the verifier can obtain the original hash, and hence, match that to a locally calculated value of the message's hash.

However, in the legal form, there is no requirement for this to be the case - a LEGAL digital signature is anything that represents the act of signing a message - hence, a cryptographic signature attached by hand is a legal digital signature; however, simply typing your name at the bottom of an email is *also* a legal digital signature.
Conversely, having a machine attach your name (or a Cryptographic signature) to a message is NOT a legal digital signature - the key is the physical act of will/choice signing the document, not the technology :)
0
 
LVL 54

Expert Comment

by:Joe Winograd, EE MVE
ID: 39974124
Dave,
One other thing. If your interest is primarily in digital signatures for PDF documents, take a look at this comprehensive white paper (152 pages!) by Bruno Lowagie, the CEO of iText Software:
http://itextpdf.com/book/digitalsignatures20130304.pdf

Regards, Joe
0
 
LVL 33

Expert Comment

by:Dave Howe
ID: 39975192
@Joe: That's an excellent document :)
0
 
LVL 54

Expert Comment

by:Joe Winograd, EE MVE
ID: 39975375
@DaveH,
I think so, too. Reading it cover-to-cover is on my bucket list. :)
0
 
LVL 33

Expert Comment

by:Dave Howe
ID: 39975536
Well, its quite short compared to this little lot:

http://www.adobe.com/devnet/pdf/pdf_reference.html

I am glad to note that, despite pdf now being a (pay to play) ISO standard, adobe still have it on their website for free download :)
0
 
LVL 54

Expert Comment

by:Joe Winograd, EE MVE
ID: 39975616
Yeah, I downloaded the 1.6 ref a while ago — 1,236 pages! That one is post-bucket list. :)

Btw, NJD posted a new question that you might want to play in:
http://www.experts-exchange.com/Security/Operating_Systems_Security/Q_28404166.html

Cheers, Joe
0
 
LVL 33

Expert Comment

by:Dave Howe
ID: 39975678
1.7 is even bigger, plus the 1.8/1.9 "extensions" that are still numbered 1.7 now ISO owns the standard :)

As for the other question - I saw it, but it seemed to me you and Giovanni had it covered, so I didn't think my input would help any :)
0
 
LVL 54

Expert Comment

by:Joe Winograd, EE MVE
ID: 39975973
Thanks for the heads-up on 1.7/1.8/1.9 — haven't even looked at 'em yet!
0

Featured Post

Complete VMware vSphere® ESX(i) & Hyper-V Backup

Capture your entire system, including the host, with patented disk imaging integrated with VMware VADP / Microsoft VSS and RCT. RTOs is as low as 15 seconds with Acronis Active Restore™. You can enjoy unlimited P2V/V2V migrations from any source (even from a different hypervisor)

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Avast Internet Security blocking QuickBooks 2017 email 10 231
GPO denied - but why ? 6 51
Web Site Administration Tool - Security Questions 2 32
wifi security 11 37
Ransomware continues to grow in reach and sophistication, putting data everywhere at risk. Learn how to avoid being caught in its sinister clutches with these 11 key tips.
Keystroke loggers have been around for a very long time. While the threat is old, some of the remedies are new!
Email security requires an ever evolving service that stays up to date with counter-evolving threats. The Email Laundry perform Research and Development to ensure their email security service evolves faster than cyber criminals. We apply our Threat…
Nobody understands Phishing better than an anti-spam company. That’s why we are providing Phishing Awareness Training to our customers. According to a report by Verizon, only 3% of targeted users report malicious emails to management. With compan…

738 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question