A digital signature (not to be confused with a digital certificate) is an electronic signature that is used to authenticate the identity of a message sender or document signer, and usually to ensure that the original message/document content is unchanged (document integrity).

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EAP-TLS fragmentation implementation

I am trying to build an EAP-TLS client. The handshake I have to deal with involves receipt of fragmented messages from the RADIUS server. As a part of the client reply, I have to construct a ...
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51 views

PDF Digital Signature [closed]

I got free certificate from Comodo and installed on my Windows. Now I'm trying to sign PDF document using this certificate, but get message: "signature validity is unknown": Why is this? How I can ...
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50 views

Testing Digital Signature Verification

I'm testing a system which involves updating a database using files sent from external parties. These files sent from external parties are basically just large flat files to update a database. The ...
2
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1answer
87 views

How does signing work with Elliptic Curve Crypto?

So I have read up and have a decent understanding of how the crypto works with Elliptic Curve Cryptography. I also think I have an understanding of how signing works with things like Elliptic Curve ...
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0answers
20 views

What curve and key length to use in ECDSA with BouncyCastle

I'm developing a client/server system in Java which is not interacting with third party software, so I don't have to worry about compatibility. At a certain point, I need the client and server to ...
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35 views

Generate a public key certificate signed by CA with OpenSSL [migrated]

I am working on a webservice that requires a signature in the sent and received messages. After sending a certificate request to the entity that will consume the webservice, they sent me (in addition ...
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51 views

Digitally sign all outbound data [closed]

I want to digitally sign all outbound data from my computer. Can someone suggest a way to do this programatically or using some tool? Instead of actually signing the data, I would simply append a ...
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2answers
129 views

Clarifying MITM attacks and Digital Certificate requirement

We are running a Portal application for our client with Payment Gateway integrated. Payment gateway uses SSL as it is suppose to be . The concern for me is that our Portal application does not use ...
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1answer
27 views

Digitally sign all the packets from client machine

If I insist on digitally signing all outgoing packets from my computer, would it affect my browsing experience? I mean if a website doesn't expect me to sign my packets, and still I sign them, can I ...
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3answers
47 views

Public key encryption vs Digital signatures

For same chunk of data, which one is faster? Public key encryption or digital signature? Confidentiality is not important. I am trying to achieve non-repudiation for the communication. Thanks!
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2answers
100 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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0answers
57 views

digitally signing a document [closed]

I've been asked to implement digital signatures for documents at work. I really need to read up more on the matter but several searches didn't make an obvious approach stand out. Main features I ...
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1answer
53 views

Trust on certificate authorities

If I as layman don't err, there are in banking controls, from both internal and national oversights, of the work done by the employees. These are apparently effective, since the details of ...
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24 views

How digital certificate works? [duplicate]

I am trying to understand the digital certificate concept , but I am confused , Below goes my understanding & question, We are using Digital certificate because if Bob & Alice share their ...
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2answers
83 views

RSA-Based Signature Algorithms

From Beginning Cryptography with Java - chapter 4, digital signatures: Signatures are created using the RSA algorithm by applying the RSA algorithm using the private key and then distributing ...
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0answers
32 views

Algorithm to Transaction Data Signing

Transaction Data Signing I need an idea to develop a very secure algorithm to authenticate online operations using PHP in the server and an Android app in the user's device. What is the idea? The ...
2
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1answer
80 views

Why do I have keys of strangers in my GPG keychain?

I'm going though my GPG keychain. I've got a key for a few strangers in my keychain. I don't recall exchanging keys and I'm not sure how the public keys came to be installed in the keychain. I think ...
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3answers
90 views

What part of the CSR is hashed in order to create its signature?

I'd like to change the CSR before it is transferred to the CA without going through the CSR creation process again. To do that I need to know how to calculate the signature of the CSR after I modified ...
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1answer
45 views

Is this signature methodology secure?

I'm working on authentication for my JSON-RPC API and my current working strategy is using signed requests sent via POST over SSL. I'm wondering if anyone can see any vulnerabilities that I haven't ...
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1answer
79 views

Is there an algorithm to generate digitally signed URL links?

Scenario: Alice prepares an URL link to Bob's web service (e.g., http://www.bob.com/sensitiveData/123?login=mallory). Alice gives the URL link to Mallory. Mallory follows the link to trigger an ...
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4answers
106 views

Can a certification authority sign another CA's certs?

Disclaimer: I have low knowledge of X.509 and PKI, so I would appreciate an answer that is not entirely technical, i.e. by using real-life example scenarios.) I was searching for information ...
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1answer
92 views

Is it possible to add backdoor to a file with the same size and crc32 checksum (4bytes)?

Is it possible to add backdoor to a file with the same size and crc32 checksum (4bytes)? (The file does not contain byte code, it contains program code as text. The language is PHP.)
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4answers
76 views

Does a PGP signature provide integrity verification?

Many websites including OpenSSL's website provide downloads along with MD5/SHA1 checksums sometimes in addition to PGP signatures for the files. Simply put, do PGP signatures provide file integrity ...
2
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1answer
56 views

IKEv2: Why is it important “that each side sign the other side's nonce”

I am currently diging deep into the IKEv2 protocol. In the description of the Authentication (RFC5996, p. 48), the following statement is given: "It is critical to the security of the exchange that ...
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1answer
187 views

SSL Certificate framework 101: How does the browser actually verify the validity of a given server certificate? [duplicate]

Sorry I know this is a complete noob question and at the risk of posting a somewhat duplicate topic. I have a basic understanding of public/private key, hashing, digital signature... I have been ...
2
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1answer
103 views

How to sign data with OpenSSL 0.9.8?

I am building a license generator for nodejs and I am currently testing on Heroku. On my local machine running OpenSSL 1.0.1g, I'm able to test my key pairs (sign and verify) like this: # data.txt's ...
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2answers
60 views

Is it possible to sign/verify a key-pair?

We currently have the need to authenticate and verify generated keypairs. Our system allows users to register for our service which generates them a key-pair for use on our network. We are in need of ...
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1answer
42 views

how to verify file signature by client PGP

Currently working on verifying and signing a file via GNUPG, given that I've already signed a file, given the clients the .sig and public key, is there a way for a client to verify the file without ...
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3answers
69 views

Does HTTPS retrieval, among its other effects, sign a document? [duplicate]

Does HTTPS retrieval, among its other effects, sign a document? I'm asking in hopes of understanding in more specific details what TLS accomplishes. I will try to elaborate my question, as follows. ...
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0answers
87 views

Digital signature based authentication schema using two passwords

I'm working on an authentication system for a web based Bitcoin-related service. As part of the service, users do some less sensitive operations (mostly reading and sending various types of ...
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1answer
55 views

Is long-term validity definitively corrupted upon TSA certificate revocation?

Suppose a document that was signed with a long-term signature (e.g. CAdES-A): D S T1 (D - document, S - signature, T1 - time-stamp created using a time-stamping certificate C1). If C1 appears in the ...
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2answers
39 views

Attack Signatures books [closed]

I have an assignment to do for school which involves attack signatures (I have to do a service-specific IDS). Basically what I have to do is to generate signatures for some attacks with Metasploit on ...
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1answer
78 views

Digital Signature Software

What is the digital signature software? What it takes to digitally sign software? I'm using the Kaspersky antivĂ­rus and the software I wrote, in Delphi, is flagged by the antivirus software due to ...
2
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1answer
412 views

Certificate verified using two different paths

StartSSL has an intermediate certificate that they use to sign their EV certificates: sub.class4.server.ca.pem. This certificate's issuer is shown by openssl x509 to be /C=IL/O=StartCom ...
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175 views

What popular online services allow passwordless authentication using digital signatures? [closed]

I am looking for web services that allow clients to authenticate using digital signatures. Especially with e-commerce and payments, clients generally authenticate using name and password (sometimes ...
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1answer
160 views

Which mail clients support PGP/MIME - is there an overview? [closed]

Does anyone know if there is a current overview (I only found ones from before 2006) which MUAs (mail clients) do support PGP/MIME? I wonder whether there still exist issues like "Outlook Express ...
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0answers
52 views

Is the digital declaration just an obscure proposal?

One professor from my university proposed me and some colleagues to work on a paper about the digital declaration (which is supposed to be better than the digital signature) for passing the subject. ...
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2answers
247 views

Digital Signatures of XML, PDF and Office Documents on every platform

I'm trying to develop a website that performs digital signatures on client-side and then sent the signed document to the server-side. I want to do the signatures on client, due to the fact of not ...
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3answers
147 views

Is it ok to send user's private key away, even if protected with a SSL channel?

I'm developing a webserver that performs digital signatures of (xml, pdf and office) documents and then validates those signatures. My idea is: an user puts its SmartCard and through a PIN, he gets ...
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4answers
64 views

Is it ok to send user's private key away, even if protected with a SSL channel? [duplicate]

I'm developing a webserver that performs digital signatures of (xml, pdf and office) documents and then validates those signatures. My idea is: an user puts its SmartCard and through a PIN, he gets ...
1
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1answer
67 views

Digitally signed scripts as a way to thwart XSS

As a blanket approach to dealing with XSS attacks, rather than having to remember to escape user-generated code, is there a way to instruct the browser not to execute any script or script-function ...
6
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1answer
105 views

Reading older mails signed with a certificate that has meanwhile expired

A few years ago I have used S/MIME certs to sign (and encrypt) my mails. The reason for which I stopped signing was the following: My (class 2) cert was issued on Jan. 1st 2008 (just a sample). It ...
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1answer
54 views

How to modify a certificate using getTBSCertificate() method

I want to show that if I modify one bit or byte from a given X509 certificate the signature verification results false (because this modification results different hash value from the certificate). ...
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1answer
142 views

valid PDF signature without using hardware HSM or usb Token

I have a DMS system(alfresco) that needs to sign approx 50.000 valid signatures a year. The signing certificate needs to be acquired from one of the affiliated sub-CA's. So according to the Adobe CDS ...
3
votes
1answer
137 views

Internal code-signing certificate on Windows

I'm looking to improve defense-in-depth on a system, primarily by closing some holes in injected DLLs. Certain applications installed on the system cause helper DLLs (e.g. shell extensions, BHOs, ...
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3answers
992 views

inquiry about SHA1 with RSA for certificate signature

As you all know, plenty of X.509 Certificates use (PKCS#1 SHA1 with RSA encryption) as the Certificate Signature Algorithm for generating the signature of 2048 Bits long. We know that SHA1 hash ...
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0answers
124 views

How to check executable code signing signatures?

How can I see all code signing signatures an executable has? I know that requests for a tool are usually considered as opinion based, but I really can't find one and I don't expect many answers. ...
0
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1answer
134 views

RSA vs ECDSA for VANET Security

I am doing a project on Vehicular Ad-Hoc Network Security (VANET). The proposed scheme uses electronic signature as a means to authenticating the nodes. Most of the research papers I read suggested ...
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4answers
126 views

How to verify full USB drive's digital signature

There are various ways to verify the validity of a file, usually checking the MD5 checksum or OpenPGP signature. Is it possible to do the same for a full USB Drive? I'd like to be able send a USB ...
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2answers
111 views

Digital signatures and truly validating what was actually agreed to

I am developing an application and part of signing up requires a user to sign a contract agreement of using the service. I have been reading around the subject for a few days, and I am fairly happy ...