Questions tagged [digital-signature]

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).

Filter by
Sorted by
Tagged with
3 votes
1 answer
478 views

OIDC ID Token nonce as "poor mans digital signature"

In absence of better solutions, is the nonce is an OpenID Connect ID Token usable to serve as digital signature. The process would be as follows: A hash is created from the to-be-signed document/...
0 votes
1 answer
249 views

How to get a CA into a Trust Chain

I'm using Google CA Service Provider in the Google Cloud to issue key materials on their FIPS-140-2 Level 3 HSMs (google's service). I intend to send the attestation bundle alongside public keys and ...
24 votes
4 answers
24k views

Verifying android application integrity from server side

I have android applications (Mobile banking) that connect to my server and do online transactions (via Internet/USSD/SMS), I want to make sure those clients are not tampered with and are the original ...
0 votes
1 answer
312 views

Over what fields is the X509 hash computed over? [duplicate]

Is this how X509 certificates are verified to be valid? The receiver receives the certificate Look at the issuer of the cert, and find the public key of that CA (its hardcoded in the application or ...
0 votes
2 answers
121 views

What could be the correct and secure ways to store and manage public keys?

I am developing an open source project(PKDSA) that uses ED25519 and ED448. My purpose of this project was to help others to enable user-secretless based passwordless authentication. There're a lot of ...
1 vote
1 answer
179 views

How does the client get the certificate (and public key) of the delegated authority (OCSP responder) to confirm the response in OCSP?

I have one question regarding the OCSP protocol to check if the certificate is revoked or not. The question is about checking whether the intermediate CA certificate immediately below the root CA is ...
1 vote
1 answer
103 views

qualified e-signature long-term security

I'm considering to obtain a QES (Qualified electronic signature). But I'm concerned about long term security. The hypothetical scenario is lets say after 10-15 years the algorithms are cracked or ...
5 votes
1 answer
3k views

What is the difference between PKCS#7 and CADES, PADES and XADES?

I am newbie in PKI. For signing a pdf documents we are free to consider each pkcs#7 format or PADES format. If I have some misunderstandings, please turn it on for me.
0 votes
3 answers
263 views

Need for authentication in an offline system

I need to design a scheme, where access to an offline System is granted based on some kind of information/proof of knowledge, provided by a separete system, Prover system. I'm in position where I can ...
11 votes
3 answers
844 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 ...
120 votes
6 answers
49k views

Why should one not use the same asymmetric key for encryption as they do for signing?

In an answer to a question about RSA and PGP, PulpSpy noted this: It is possible to generate an RSA key pair using GPG (for both encryption and signing -- you should not use the same key for both). ...
-1 votes
1 answer
300 views

Device authentication, common method

What are some standard device authentication methods, in a scenario when: The desktop computer is being authenticated on web service I provide the .exe on the desktop I control the web service The ...
0 votes
2 answers
343 views

Does verifying a code signature require making a network connection?

Does Windows 11 need to make a network connection to verify a code signature for a .exe or .dll file?
13 votes
3 answers
3k views

Is it possible to use WebAuthn for digitally signing documents in the browser?

WebAuthn is a relatively new API for authentication, and it uses public key cryptography instead of something like passwords. I am wondering if it is possible to use the cryptographic part for a ...
5 votes
0 answers
297 views

What's the merit of storing LTV (long term validation) information for RFC3161 tokens and what happens if a TSA private key would leak?

I'll formulate my question in regards to timestamped PDF, but I wonder actually about the long term validation of RFC3161 tokens in general. So, PAdES has the concept of Long Term Validation, which ...
-1 votes
2 answers
1k views

Request/Creating a Code Signing Certificate

I have a need for a code signing certificate which is trusted by a CA in the Windows domain. How do I request/create this certificate? Do I have to request a code signing certificate on the ...
1 vote
1 answer
661 views

Strip CMS Signature from file (using openssl?)

I have a lot of binary files that contain some data that is signed using CMS. The files have the form: $ openssl cms -inform DER -in test.cms -cmsout -print CMS_ContentInfo: contentType: pkcs7-...
3 votes
0 answers
453 views

Secure boot + full disk encryption, should I sign the kernel?

I'm redoing my laptop installation from scratch, and this time I want a full secure boot chain. Here's what I did so far : Enroll my own keys in the UEFI firmware Sign my grub bootloader Full disk ...
1 vote
1 answer
309 views

Prove Alice Had Sent the Message Before

Alice just sent a message to Bob, but prior to that she had already sent the very same message. How can Bob prove that?
1 vote
1 answer
88 views

What is the most secure hardware option for the use of personal eIDAS compliant QES in the EU?

I know that there are two approaches, one with local capsulated storage, such as USB token or smartcard, and the other with cloud-based key vault. Both are secured with a PIN that has to be entered in ...
1 vote
0 answers
116 views

Is there any use case of DAA (Direct Anonymous Attestation) in TPM?

I want to know the use cases of DAA (Direct Anonymous Attestation) in the real world.
0 votes
0 answers
31 views

Is it possible for an app to sign data it generates so that the data can be guaranteed to come from the app? [duplicate]

Is it possible for an app binary to sign content generated by the app such that a verifier can confirm the data was indeed generated by a specific version of the app? For example: A mobile app from a ...
1 vote
1 answer
97 views

Confusion Regarding TLS Handshake and Key Exchanges

I know much has been written on this topic, but I am still stuck on some on the details of TLS handshake and I would like to have a better understanding of what happens. I've been using several ...
1 vote
5 answers
527 views

How does a digital certificate prove authenticity?

Imagine the following scenario: We have Bob that wants to send a message to Alice. Both have a public/private key. Bob uses his private key to sign the digest (hash of the message) with it's private ...
-1 votes
2 answers
3k views

How to generate SSH keys inside yubikey?

How do I generate SSH keys inside my yubikey, on Ubuntu? There seems to be nowhere to look for this info.
5 votes
1 answer
546 views

Does signing of HTTP requests have any benefit when using TLS?

Signing HTTP requests is all the rage nowadays. The benefits of doing so when communicating over an insecure channel are clear. With signatures you can bring message integrity and authentication to ...
1 vote
0 answers
156 views

mTLS on webhooks

I'm not understanding how does Sendgrid verify that's it's me who's sending them the HTTPS request on their webhook endpoint. Specifically, in their docs they show how to obtain their public key (to ...
5 votes
3 answers
638 views

What's the purpose of signatures in Google Maps APIs?

There's something I don't understand about signatures in Google Maps APIs. The documentation says "We strongly recommend that you use both an API key and digital signature, regardless of your ...
0 votes
4 answers
953 views

Token FIPS 140-2 level 3 with support for Android, iPhone and Web

I'm testing a SafeNet 5100 token FIPS 140-2 level 3. It comes with programs to access and manage it, but only for desktop machines. I would like to create applications that use level 3 tokens. Is ...
8 votes
1 answer
6k views

ADFS: Verify requests from relying party

In ADFS, serveral certificates are used. This is explained (very clearly) on this page: http://blogs.technet.com/b/adfs/archive/2007/07/23/adfs-certificates-ssl-token-signing-and-client-authentication-...
1 vote
2 answers
220 views

HSM High Volume Keys

Our project is to apply digital signature to PDF, so each user should have their own key pairs and a certificate. To keep key securely, we plan to purchase HSM, but from what I understand HSM have a ...
3 votes
2 answers
28k views

OpenSSL check if a SSL certificate is SHA-1 or SHA256 signed

How do I check if an OpenSSL certificate issued to a site is SHA-1 or SHA-256? I have a quite a lot of intranet sites using OpenSSL certificates and I am a bit confused as when I check the certificate ...
1 vote
1 answer
152 views

Does signing make any sense when encrypting with secret key is used?

When I use secret key which only one server know for symmetric encryption done with XChaCha20-Poly1305, is any benefit to use signing aswell? As long as only one server knows the secret, doesn't it ...
47 votes
2 answers
81k views

What is the actual value of a certificate fingerprint?

In a x509 digital certificate there is a "certificate fingerprint" section. It contains md5, sha1 and sha256. How are these obtained, and during the SSL connection, how are these values checked for?
0 votes
1 answer
920 views

Signing HTTP requests with JWS

Looking over the spec for JSON Web Signature (JWS), I realise that it doesn't seem to specify anything that is HTTP-specific in terms of the payload. Specifically, signing HTTP headers and bodies (say,...
0 votes
1 answer
323 views

Do git commit signatures reveal key uid if different from git email?

I have a gpg key linked to my identity and real email address. I also use github with their private email functionality "[email protected]", which I set as my git email. ...
19 votes
2 answers
5k views

What exactly happens when I "validate" a digital signature?

Context: I'm filling my taxes and my country requires me to upload certain documents from my employer to verify the numbers I give to the government. These documents are "digitally signed", ...
5 votes
3 answers
531 views

Are document signature services violating any rule by exposing PII over clear email?

A company sent me a document to sign via CudaSign, I did. As soon as I completed the transaction, I got a PDF over email with the document attached. The document includes my SSN. I assume, the ...
0 votes
2 answers
562 views

Digital signature for API authentication feasible?

Could it be practical to authenticate API request through digital signature (based on headers and message body)? This would be asymmetric instead of something like HMAC which is not a signature. ...
0 votes
1 answer
67 views

Encrypting content with assymetric key pairs as a form of signing [closed]

The use-case is as follows: There is a signer that have a claim or document D who wants any client to be able to verify that D has not been tampered with. I suppose one way to do this is to use ...
0 votes
1 answer
844 views

Forging message using the secret key in digital signature?

In Digital Signature Scheme, is it possible to forge a message just by knowing the secret key, or does the attacker should also know the hash function used by the original sender? Also does the secret-...
7 votes
4 answers
3k views

Why trust a PGP signature if it is distributed along with the data being verified?

Many downloads offer an OpenPGP signature, which can be used to verify the file, but if a hacker manages to manipulate the file, then he can also simply change the signature key, or not?
6 votes
1 answer
11k views

Where is the public key of the Certificate authority stored? [closed]

I'm talking about SSL/TLS certificate authorities. I know that they store their private key in a very secure location. But what about their public key that our browsers use? Where does it get stored ...
1 vote
3 answers
159 views

Is it normal, that some companies just sign the txt file which contains the sha value of the program?

Scenario A: Suppose I have an .exe file, the provider offers a sha1 txt file with hash value and this txt file is gpg signed. So I check if the hash value matches the exe file and then download the ...
2 votes
1 answer
1k views

Best practices for verifying authenticity of public key

When one desires to share their public key openly, besides sharing just the key itself: How does one verify that the key belongs to who it claims to be owned by? What is the use case of the key's ...
2 votes
1 answer
495 views

Why a public key must be signed with its private pair in PGP

I know about the trust web in PGP. When you sign a key, everybody that trusts you will trust the person with that key. But what is the point of self-signing a key when anybody else can do that with ...
2 votes
0 answers
852 views

Can't sign commit with yubikey, GPG missing something

I don't know much about how yubikeys work, but I'm trying to sign a commit with one of them and I don't even know how to debug the problem. I got: gpg --list-keys /home/lz/.gnupg/pubring.kbx ----------...
35 votes
6 answers
24k views

What does "signing" a file really mean?

I'm a bit new to security and trying to get the concepts properly. I'm wondering what exactly "signing" a file (a certificate, an apk file, or something else) means? Do we sign the whole file so ...
1 vote
1 answer
271 views

Public Digital Signature Validation with JWE

After reading JSON Web Encryption (JWE) and making a Node JS JWE POC demonstrating key mode using Key Encryption. I'm a bit confused as to how to validate that the sender of the message was in fact, ...
2 votes
2 answers
2k views

Are all fields of the PE certificate directory hashed during authenticode signing?

In a Windows portable executable (PE) file the certificate directory points to an offset to a WIN_CERTIFICATE structure. My understanding is that while the field is named bCertificate, it actually ...

1
2
3 4 5
18