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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With javascript in the browser, how can I sign some data without directly manipulating a private key?

With JavaScript in the browser, I need to digitally sign some data. I'm looking at the new Crypto.Subtle api, specifically the sign() and importKey() methods. I want, very reasonably I feel, to ...
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37 views

How to verify signature while downloading log4j?

From the log4j download page. The PGP signatures can be verified using PGP or GPG. First download the KEYS as well as the asc signature file for the relevant distribution. Make sure you get these ...
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87 views

RSA signature on TLS

In a TLS handshake using ECDHE-RSA, the ServerKeyExchange frame must include the ECDHE ServerPublicKey, signed with its RSA private key, as specified in the RFC 4492. Got it. Trying to implement an ...
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197 views

How to encrypt with ECDSA?

Suppose there's a transaction in the blockchain in which a given address transfers bitcoins to whoever. I need to encrypt a message so only the owner of that address will read it. I have his public ...
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250 views

Assuring Client is Authorized to use JSON Web Token

JSON Web Tokens ( JWT ) are server-signed objects that the issuing server uses to identify a user, track session data and authorize requests. The fact that JWT are server-signed gives assurance that ...
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Run our own Certificate Authority for internal use only: safe or not? [duplicate]

According to the guide at How to Run Your Own Certificate Authority, my organization have a plan to issue our own digital certificates for internal use only (the managers will sign PDF documents to ...
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195 views

What the most trustworthy way to demonstrate digital File Integrity?

I'm looking for ensure the integrity of uploaded files and demonstrate this integrity to a user. In my current scenario, a user sends multiple files in several different formats, these files are ...
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1answer
118 views

Is algorithm used to sign defined by certificate?

Using pfx certificate to sign or cypher, the algorithm used (rsa-1_5, rsa-oaep-mgf1p, etc) is defined inside pfx certificate? Certificate has information about algorithms used? Or it's totally ...
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Digital Signature and Verification?

AFAIK , When Alice wants to write a message to Bob -- she uses Bob's public key and encrypt the message - and then Bob - using his private key - use to decrypt it. So public key is used to decrypt ...
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54 views

Is there a way to sign information by when it was made? [duplicate]

Looking at this question ("Is it legal to use an online logbook?") from Aviation SE, I'm wondering if there is a way to sign information in such a way that: It ensures that there was a certain time ...
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209 views

Significance of the difference between DSA and RSA in signature verifying speed

I have run openssl speed and the output on my CPU for longest available DSA key size, which is 2048 bits: sign verify sign/s verify/s rsa 2048 bits 0.029185s 0....
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273 views

What real life scenarios require separate end user certificates for Signing and Identity?

Based on this question, I'm interested in any rational argument that would support the idea of maintaining separate signing and authentication certificates. Conventional logic & wisdom says there ...
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332 views

Electronic identity and digital signatures - why they are different?

It seems (to me at least) that is is generally accepted that "electronic identity" and "digital signatures" are a different thing. For example, in the Estonian ID card there are two certificates - one ...
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1answer
479 views

Simulation of cloud based digital signature with Hardware Security Module (HSM)

I am working on a cloud-based digital signature with a Hardware Security Module (HSM). I know that PKCS#11 AND Microsoft CryptoAPI implementation is required. I want to simulate the total process. For ...
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154 views

What encryption and signature systems (don't?) allow for plausible deniability of the OP's key being used?

I need to prevent Mallory from blindly matching encryption and signing keys to messages Hypothetical scenario: A user creates a public key An encrypted or signed payload exists. With only public ...
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77 views

Does any nation-state CA (certificate authority) have a public API to verify digital signatures? [closed]

There are around 200+ nation-states on the planet. Most of these use eIDs. Do any of these nation-states have a public API to verify digital signatures? Example: Nation-state Canada issues a eID to ...
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0answers
35 views

Nation-state digital signatures - how is my public key linked to an identity? [duplicate]

A bitcoiner trying to understand the nation-states. When I use my eID (I'm swedish and I have 'BankID'), and I sign something with my private key that's in the 'eID-file' that I've got on my laptop, ...
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3answers
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Help verifying downloaded Kali image

I am following instructions as shown here Operating Windows 7, so have downloaded GPG4WIN. Next instruction: is to enter this command: $ wget -q -O - https://www.kali.org/archive-key.asc | gpg --...
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35 views

Is there a cryptosystem that allows a set of auditors to confirm that they have valid Shamir or Group signatures?

Suppose I have a client that generates and sends a Shamir key (or group signature) to a set of Auditors. This key is essentially an unverified set of bytes. Each auditor wants to somehow verify that ...
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How do I prepare for Certificate Authority end of business?

We are deploying a security solution which uses certificates to validate documents. These certificates are issued by our government-authorized CA. What if in a distant future, the CA who provided us ...
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77 views

Understanding digitial certifications

q1) Does that mean that every time information is exchanged, both the original data + digital certification is sent? Meaning data + signature for each and every exchange. q2) Can any kind soul here ...
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1answer
730 views

How do I verify a GPG signature attached for a cleartext email using the gpg command line?

I received an email in cleartext from someone with a signature.asc attached. Looking at the raw source for the email, it was sent with Apple Mail + GPGMail. Reading the message in Thunderbird + ...
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Why can I sign but not encrypt?

-edit- After following a chain of links from this question I see this is similar/duplicate of Why should one not use the same asymmetric key for encryption as they do for signing? but this question ...
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Combinations of key exchange and signature algorithm in TLS

Let's say that one does not trust ECC a lot, and values confidentiality over authenticity (perhaps simply for the reason that MitM is more difficult than passive eavesdropping and decryption later on)....
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Untraceable Digital Cash?

I have read some articles regarding digital cash that is untraceable (Here). Their protocol is provided below Withdrawal: Alice creates an electronic coin and blinds it. Alice sends the ...
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A “good enough” digital signature, with short key

In my application, I want to hide debug feature behind a password. I don't want the password to be easily known by issuing strings executable, so I want to rely on digital signature. We want Debbie ...
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Confidentiality in Digital Signature

Recently I have been working on Digital Signature. Some common reasons for applying a Digital signature to communications are Authentication, Integrity and Non-repudiation. Does Digital Signature also ...
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53 views

Is there a way to sign a 624 bits message on 256 bits

I'm looking for a way to sign a 624 bits message on 256bits (sig length = 256 bits) with an asymmetric keys system? I'm trying to sign a qrcode so a client can be sure that this qrcode has been ...
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1answer
298 views

Difference between public key and private key validity period

In the section about certificate extensions, the ITU-T X.509 recommendation writes: The private key corresponding to a certified public key is typically used over a different period from the ...
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Parsing a PKCS7 detached signature hash

I'm trying to manually verify signatures of Apple iOS Passbook files, which are PKCS #7 detached signatures of the RSA key of the Apple developer who created the file. Which means there's a file "...
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1answer
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openssl verify signature

For S/MIME, I now know I can verify PKCS#7 detached signatures with: openssl smime -verify -in detachedsign.pem -content content.txt But what about non-MIME messages? So if I sign the message Hello,...
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1answer
358 views

Is it a safe to hardcode my secret key in my iOS app?

Cloudinary iOS SDK configuration suggests to hardcode your api_secret in your iOS app's source code. Isn't that a security vulnerability since string literals can be extracted from the app binary, e....
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Can an embedded CRL be trusted?

Embedding CRLs in a signed document will allow the signature to be validated "long term", by providing a snapshot of the signer's state the moment the document was signed. Im wondering if these ...
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Are there any meta-formats for crypto?

Are there are any (properly specified) meta-formats / schema formats for describing cryptographic message structures? I'm looking for a way to describe the format (where some channels might want ...
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How can I sign an rpm package using a smart card?

I have a smart card (not OpenPGP card), and I am preparing to sign an rpm using this card. After signing, I will get two files: my.rpm.sig, and my_id.cer. How can I sign my rpm using these extra ...
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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. ...
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Getting the DNS root name servers in a secure way

It doesn't happen often that a root name server changes, but when it does sometimes it takes months for OS vendors to provide patches and in the mean time there is a security risk. So: How to get ...
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Man in the middle attack on browser downloads

I'm writing this post from chrome. If I go to a HTTPS site after this, the public keys built into the version of chrome I'm using will be used to verify the site's signature (unless I misunderstand). ...
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1answer
319 views

Request signing for REST API

I am building a REST API that will receive requests like: GET /api/entities GET /api/entities?filter=X&sort=Y This seems straight forward: have the client HMAC(path + query, key), send me a key ...
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1answer
152 views

Is the enforcement of only allowing signed application to run in a Windows server a safe rule in a prod environment?

There are various security tools that allow an administrator to enforce only signed applications to run in a Windows operating system. is this a realistic general enforcement rule in a production ...
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CMS/PKCS#7: specifying signatureAlgorithm with digest?

I'm confused about algorithm selection for Cryptographic Message Syntax (a.k.a. CMS, PKCS#7) signed objects (RFC5652 Section 5.1). The SignerInfo structure (RFC5652 Section 5.3) has two separate ...
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1answer
226 views

Signing (HMAC) cookie identifier

Related to this other question about sharing the secret to sign the cookies, my question is more trivial: how really secure is to sign a simple cookie identifier? In example, expressjs#session ...
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How are digital certificates compared?

I have read about SSL and TLS; I know how RSA works and why digital certificates are necessary (more or less), but I am curious about how we prevent a fake digital certificate. The operating system ...
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42 views

Asymmetric Encryption Digital Signatures

Here is the paragraph I can't quite get my head around. Alice sends a message to Bob and wants him to be sure the message has come from her. • She publishes her public key. • She computes ...
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Subject verification of certificates

Suppose H has taken C’s certificate and manually changed the subject information in C’s certificate from C to H. Would this modification be detected by A during the certificate verification process?
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RSA vs DSA Digital Signature Message Digest Recovery

I'm learning about signatures using RSA and DSA, I've come across this little fact: RSA can recover the message digest from the signature, whereas in DSA this isn’t possible – you have to have the ...
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1answer
160 views

Is a handwritten scanned signature equivalent to its paper counterpart? [closed]

In terms of Authentication, Integrity and non-repudiation, is a handwritten scanned signature equivalent to its paper counterpart? For example, if you have a paper contract and you obtain a digital ...
2
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1answer
105 views

How to verify installed packages [closed]

On Linux (Debian x64) I recently installed some software with: apt-get install the_package_name APT told me some packages couldn't be authenticated but I ignored the warning and installed anyway. ...
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143 views

Can a signed downloaded file be securely verified if you only control the private key and the download/verification algorithm?

I'm designing the update procedure for IP Camera's. I'm wondering if my current design is secure enough. I have a binary file that I want to get to a device. I make a hash of this binary file and ...
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Is it possible and does it make sense to sign an E-mail with PGP and S/MIME?

After some research without any answer to my question, if it's possible and does it make sense to sign an E-mail with PGP and s/mime (?), I'm hoping to get an answer here. I know that, PGP and S/MIME ...