Non-repudiation is the ability to prevent a identified individual from repudiating a specific action or communication associated with that individual.

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Authenticity of PDF document printed from Word

My MS Word Add-In generates PDF preview of DOCX file on client PC and uploads both files to server. I cannot generate PDF on server. Is there any way to make sure that the PDF is the printed version ...
2
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1answer
171 views

How can Alice and Bob prove that they share a file?

Carl asks Alice and Bob if they have a file f such that for a secure cryptographic hash function h, h(f) = K. Both claim to have f, but they can't show the file. Carl doesn't believe them. He can ...
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96 views

HMAC and non-repudiation

This was a question on an exam: Two persons are using a one way communication channel and the HMAC functionality (concretely HMAC-SHA1). Choose the correct statement below: 1) We can prove who the ...
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209 views

How do I release a self made program without it being tracked back to me?

For clarification, I am looking for the best way to release this program anonymously, not how to remain anonymous and such in general life (that is a different -already answered- question). I've ...
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0answers
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Is it fair to say that lack of client-authentication in TLS implies no requirement of non-repudiation?

In an https context, if a server does not send a CertificateRequest message, is there any other way it can require non-repudiation from the client?
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Does Non Repudiation offer proof of receipt ?

I understand that non repudiation intends to provide a mechanism that reliably proves that the sender of a message cannot deny sending the message. But does it also provide similar mechanisms to ...
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170 views

Does SMIME differ from TLS, PGP, DMARC signature, or a Portal Encrypted email message in terms of legal non-repudiation?

I'm interested in protecting email messages from NSA-style snooping, but don't want to incur additional legal risk in doing so. In other words, does SMIME encryption and/or signing cause a given ...
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3answers
273 views

Non-Repudiation that can Never be Proven

I understand that non-repudiation is based upon public key cryptography and the principle of only the sender knowing their own private key. However, what is a condition, if any, of non-repudiation ...
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112 views

TLS with non-repudiation; what happened with 'TLS Sign'?

TLS Sign was proposed as an IETF Draft in June 2007. I have not found further information, besides that the draft expired in November 2007. Can someone tell me what happened with this extension or ...
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1answer
195 views

How online document signing services guarantee non-repudiation?

There is a number of services online like RightSignature or SignHub that will let you sign online legally binding documents. I understand how documents can be signed digitally and this can guarantee ...
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1answer
486 views

Secure API access over SSL using oauth token

On the project that i'm currently working, we authenticate the clients by username and password. In this system each user has a key which is calculated from his password. However, we want to provide ...
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3answers
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Is “non-repudiation” automatically proven, given the other three tenets of info security?

Just to say it, the four tenets are: Confidentiality - The message the recipient gets can be proven not to have been read by anyone else since it was encoded. Integrity - The message the recipient ...
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What security standards and regulations are in place for bank ATM?

Are there any international or US mandated standards and regulations that apply to communications between automatic teller machines and bank's central office? Are banks or ATM operators subjected to ...
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1answer
115 views

Ciphertext for email vs Ciphertext for database

Let's say Bob wants to send a message to Alice. This communication requires to achieve confidentiality, integrity, proof of origin, non-repudiation. Therefore we can use this cipher-text: ciphertext ...
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2answers
4k views

When using symmetric key encryption, do we need to sign?

Say we're using a shared key between two parties, that has been distributed using public key encryption, is it still necessary to sign any data that's encrypted using the shared key? Or is it enough ...
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4answers
15k views

What is the difference between authenticity and non-repudiation

I'm new to infosec and doing some reading. Not surprisingly one starting point was wikipedia. In this article, authenticity and non-repudiation are listed as 2 separate 'Basic concepts'. My ...
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4answers
836 views

Non-repudiation in Exchange/Outlook without Digital Signatures

Scenario: Acme Corp. needs to collect evidence to support their side of a case in court. Part of this evidence may include e-mail messages. Certain employees who do not have administrative access ...
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4answers
17k views

How to achieve non-repudiation?

If I have a message that I need to send to another person, how do I achieve non repudiation ? Is digitally signing the message sufficient ?