I am a novice programmer who is implementing a digital signature for a PDF doc. I want to know the standards used in the industry to sign and verify the document.
A stepwise approach from key generation to verification of document works for me.
There are ISO standards and RFCs for digital signatures.
But the above have many many options. So the real question is "which profile for digital signatures is most recommended?" The answer is PAdES. It is supported and used by Adobe, DocuSign, and all of the significant players.
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I'm looking to automate data entry from predefined forms that have been filled out by hand. The characters are not separated, but the fields are identifiable by lines underneath or as a part of a table. I know that handwriting OCR is still an area of active research, and I can include an operator review function, so I do not expect accuracy above 90%.
The first solution that I thought of is a combination of OpenCV for field identification (http://answers.opencv.org/question/63847/how-to-extract-tables-from-an-image/) and Tesseract to recognize the handwriting (https://github.com/openpaperwork/pyocr).
Another potentially simpler and more efficacious method for field identification with a predefined form would be to somehow subtract the blank form from the filled form. Since the forms would be scanned, this would likely require some location tolerance, noise reduction, and feature recognition.
Any suggestions or comments would be greatly appreciated.
As said in Tesseract FAQ it is not recommended to use if you're looking for a successful handwritten recognition. I would recommend you to look more into commercial projects like Microsoft OCR API (Scroll down to Read handwritten text from images), you can try it online and use their API in your application.
Another option is ABBYY OCR which has a lot of useful functions to recognize tables, complicated documents etc. You can read more here
As for free alternatives - the only think that comes to mind is Lipi toolkit
As for detection of letters - it really depends on the input, in general if your form is more or less same every time - it would be best to simply measure your form and use predefined positions in which you need to search for text. Otherwise OpenCV is a right technology to look for text, there are plenty of tutorials online and good answers here on stackoverflow, for example you can take a look at detection using MSER answer by Silencer.
I am using cryptography to implement some blockchain application, after I looked code, I don't know how to distinguish SHA2-256 and SHA3-256.
The Elliptic Curve Digital Signature Algorithm (ECDSA) supports any hash function not limited to the SHA family, as MD5. SHA-3 should be supported, yes, indeed, I recommend using it as it is a open contest standard and improves security.
can I say that some value added services in a mobile game or application are VAS?
I have a challenge with myself because i heard that VAS is specialy for the communication services.
VAS is commonly used in the telecom industry, it's true.
But it is a vague term, that can be used by anyone - see the Wikipedia page. . There's no legal meaning to these words.
I think you can use it if you have added value to something that is generally accepted as an industry standard, or a necessary service.
I need an obvious example about AES decryption. i just want to know how it works in order to make my own coding of this algorithm so, I neither want code nor algorithms, i just want some explanation of how it works, I need to understand it first before i can make an implemetation fir it. Can someone give me tutorials or references?
How about Moserware's A Stick Figure Guide to the Advanced Encryption Standard (AES)? It's clear and entertaining. Don't forget to sign and date the Foot-Shooting Prevention Agreement.
Apparently Apple has changed some term in the agreement again.
From http://www.appleoutsider.com/2010/06/10/hello-lua/
section 3.3.2 is now
Unless otherwise approved by Apple in writing, no interpreted code may be downloaded or used in an Application except for code that is interpreted and run by Apple’s Documented APIs and built-in interpreter(s). Notwithstanding the foregoing, with Apple’s prior written consent, an Application may use embedded interpreted code in a limited way if such use is solely for providing minor features or functionality that are consistent with the intended and advertised purpose of the Application.
instead of the original
No interpreted code may be downloaded or used in an Application except for code that is interpreted and run by Apple’s Documented APIs and built-in interpreter(s).
I am more interested in embedding Lua, but other people have other embeddings they want to make.
I am wondering how you ask for permission, and what they mean by the terms "minor features" and "consistent" and how will Apple interpret this section? It seems to have enough loopholes to drive a real firetruck through.
(BTW this is a terribly important question for me an my product.)
Realistically, the ultimate interpretation of the developer agreement is up to Apple.
Since this is all new, it's not clear who to e-mail. You could start with the iTunes Connect people, but be prepared for a long wait to hear back. Alternatively, I've gotten some occasional quick help just by calling up the nice Apple people in Ireland.
Given the wording , if you want to embed Lua, you should be prepared to justify that you will be using Lua in a limited fashion to provide minor features or functionality.
Since you've stated this is a really important question, you might want to consider the risks inherent with pushing the envelope/being a pioneer. If there's an alternative way to get around all this, you should consider it. If there's no way around it, it might make more business sense for you to pursue another platform for now.