Essential Signature Program Interview Questions & Answers:

1. Explain Does XML Signature provide for non-repudiation?

The specification does not speak of non-repudation for the following reason. An XML Signature associates a specific key with a specific message such that it is computational infeasible for anyone without the key to alter either the message or the signature without the signature under that key being broken. Consequently, the specification speaks of signer authentication. Note that the use of assymetric keys does provide for technical non-repudation because only one person need have access to the key. However, when symmetric key algorithms (like HMAC) are used both the sender and receiver have access to the key. Furthermore, non-repudation is frequently defined in the context of the trust model and concerns itself with the trustworthiness of key distribution and revocation. Consequently, we avoid the term non-repudiation.

2. How to print sum of two number without using main function?

by using functions
eg:

main()
{
sum();
}
sum()
{
int i,j;
printf("enter i,j values:");
scanf("%d%d",&i,&j);
printf("%d",i+j);
}

3. If there are multiple elements in the same document. How do sign the elements plus the order in which the elements appeared in the document?

Do not uses multiple references. Instead, use an Xpath transform, since the expected result is that the elements included by the Xpath are given in document order.

4. Explain What will be the output of the expression 11^5?

by using functions
eg:

main()
{
sum();
}
sum()
{
int i,j;
printf("enter i,j values:");
scanf("%d%d",&i,&j);
printf("%d",i+j);
}

5. How to combine XML document with a signature such that, in the resulting document, the signature signs the original document?

1. Create an enveloping signature around the root element of the document.
2. Create an enveloped signature. The signature is placed inside the document, and its SignedInfo Reference contains transforms that omit the signature from the document.

6. Explain How a C program will execute(run) automatically even though you have not runned it?

by using functions such as:

main()
{
sum();
}
sum()
{
int i,j;
printf("enter i,j values:");
scanf("%d%d",&i,&j);
printf("%d",i+j);
}

7. Explain How to create a signature over some content at a URL such that can change the URL without breaking the signature?

Use Reference in a Manifest to indicate the content by URI. Reference in Signature should indicate Manifest but should have transform that omits URI. Thus, URI can be changed without breaking signature.

NOTE: Core validation does not validate digest values in Manifest (only in SignedInfo), so the application must validate the Manifest after calling upon core validation.

8. How to sign multiple data objects with the same signature?

SignedInfo can have multiple references.

9. Explain Which language should be learn for getting better job?

C language should be learn for getting better job.Because C language
is a basic of computer language.without c no other language
is important.

10. How do sign a single data object with multiple keys?

Create a seperate Signature for every key that you want to apply to SignedInfo and its data objects. To remove redundancy where SignedInfo includes many references, create a single Manifest with each Signature referencing that single Manifest.