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1answer
62 views

What are the steps of hashing and steps of verifying password using salt and key? [duplicate]

What are the steps of hashing password during registration and login to an application using salt and key? Are the following steps considered correct if applied to an application?: 1- During ...
0
votes
1answer
59 views

Updating Sender-Keys and Key-Management

This question is related to an earlier question I had: Encryption on Mobile Devices - Multiparty Encryption - Key Management My situation: I have many mobile devices that want to send sensitive ...
0
votes
0answers
46 views

Public blockchain, encrypted blocks with access list; Key revocation; Is it a fit for attribute based cryptography?

I've got the requirement to put the company data onto blockchain for traceability and auditability. Some of that data is public, whilst some of this data is confidential to 1+ (could be many) user ...
2
votes
3answers
174 views

In PGP how can I be sure about the public key?

I was reading about Protonmail's system and I couldn't find an anwser to something. In PGP communication is encrypted using assymetric cryptography: public and private keys. If you want to send ...
0
votes
2answers
261 views

Understanding AES Keys and Passphrases

I am trying to get my head around how AES works and in particular I have queries around the key generation and 'passphrases'. My understanding is that AES has a 128 bit block size but the key length ...
0
votes
2answers
115 views

What factors should I consider when choosing the key for encryption and decryption?

We have an application that uses cookies to transmit employee personal data over from the front end to the server. We have planned to use TLS 1.2 for the encryption in transit. However once the java ...
0
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0answers
30 views

Know the setting used in creating key pair in GNUPG4Win version 3.15

I am using GNUpg4Win version 3.15. For the last few hours I am trying to figure out what default settings are used for Cipher and Hash during key generation. Basically I want to use AES-128, 3DES ...
2
votes
1answer
278 views

One GPG key with multiple user identities for my career?

I am trying to work out what is the best approach for managing GPG keys over my career when I change jobs. My understanding is that there are two ways this could be done: Have one main/master GPG ...
4
votes
1answer
140 views

What fundamental problems are solved by using a Key Encrypting Key (KEK)?

I've read several questions regarding KEKs but have not quite found one that comprehensively addresses why we would choose to use a KEK. This excellent answer by Mike Ounsworth explains how KEKs allow ...
2
votes
2answers
77 views

Security Appliance Key Generation

For devices like decrypting HTTPS proxies, there is often a built-in mechanism for generating a key-pair and CSR. An admin can then have their in-house authority sign the CSR with a subordinate CA ...
1
vote
0answers
187 views

Android Secure Keystore pre-API 19

Is there any secure Keystore for Android other than Android Keystore? If an attacker used an emulator, saving a key in SharedPreferences or storage is pretty much useless since she'll have direct ...
4
votes
1answer
344 views

Generate subkeys based on less secure OpenPGP primary key

I've been reading about the benefits of using OpenPGP subkeys for different machines. Obviously, it's a much safer practice than copying around the same master key between multiple machines (...
3
votes
2answers
319 views

What is sent between an HSM and an application?

When an application calls an HSM using PKCS#11/KSP/etc. what is actually exchanged between the two? For example, if a CA needs to sign a CRL, is the entire CRL actually sent to the HSM for signing?
0
votes
1answer
128 views

Encrypt content such that it can decrypted only by a specific application

Is there a key management approach for the following scenario: Customer Alice uses an application S1 to generate a file. The contents are expected to be encrypted such that it can only be decrypted ...
2
votes
2answers
885 views

Can recovery of decrypted text possible with memory dump with root privilege in Linux?

Suppose Alice and Bob are communicating using secure channel and both use symmetric key algo (AES) for encryption/decryption. The scenario is like 1. Alice encrypt data M1 with secret key K and ...
2
votes
1answer
339 views

What is a secure DNSKEY bit length and usage time?

During penetration testing I have seen DNSSEC keys with lengths of 1024 and 512 bits. NIST recommends a key length of at least 2048 bits. So is it correct to assume that these DNSKEY's are unsafe to ...
1
vote
2answers
160 views

Securing passphrase on DB

I have stored encryption keys on the database that are encrypted with a passphrase. To decrypt it the owner/user must login using his passphrase, and that will be used to decrypt the encrypted keys on ...
1
vote
1answer
319 views

What are Encryption/Decryption Key Management Best Praticies [closed]

I am developing a web based application that will be employed by numerous third party organisations in numerous countries around the world. The browser based client will feed sensitive data into a ...
4
votes
3answers
435 views

Is public-key encryption the correct choice?

Note: I orignally posted this over on Crypto Stack Exchange, but was pointed here instead I'm working on a project which requires encryption of sensitive data, with communication of said data between ...
0
votes
2answers
7k views

C# .Net most secure way to store RSA Key Pair in Windows

At the moment I am looking into the most secure way to store a private RSA key on Windows. Making it as much usable for the end user as possible, while keeping the security to its highest. As this ...
2
votes
2answers
217 views

Does unsecure delivery of keys and certs make a VPN useless?

I had to install an OpenVPN service onto a fresh, disconnected computer, but the keys and certs were delivered through an insecure computer with a highly suspect connection. Let's assume that the ...
1
vote
1answer
117 views

Hide data from user, but process it in application

Is there a way to hide the data that's received somehow from the user? In particular, I have some data that gets send from a webserver to an application. I want the application to process the data, ...
9
votes
1answer
296 views

How to compare key management strategies

Are there formal security definitions or frameworks to evaluate the quality of a key management scheme? Can I state something like "the key is XYZ-protected against a polynomial adversary given that [...
2
votes
1answer
73 views

Revoking AIK Key

How can I prevent attacks via compromised Attestation Identity Key (AIK) keys, such as having an attacker forging the cryptographic signature of an AIK key on TPM?
3
votes
2answers
1k views

Can TPM “Storage Keys” be created outside the TPM?

I am interested in 'adding' preexisting keys to a TPM's storage hierarchy. An example of a desired key hierarchy can be shown as: (SRK)----->(User Storage Key)-------> User Working Key 1 ...
1
vote
0answers
70 views

Checklist for Data Communication Review in ERP Solution

I am looking out for a checklist for data communication review within ERP application. I understand some of the checks would be related to digital signature, TLS/SSL use, Key Life Cycle management ...
4
votes
2answers
454 views

Sharing RSA keys between PGP and SSH protocols: Does this pose a security risk?

If I generate a PGP subkey that only has the authentication capablity and use this to generate an SSH keypair to authenticate Git for example, does this pose a security threat? When I do, should I ...
7
votes
2answers
5k views

Is HTML5 sessionStorage secure for temporarily storing a cryptographic key?

Assume I am building a local web application (e.g. browser extension) in HTML5 to encrypt a database locally. Access to the database is controlled by a password and a cryptographic master key is ...
2
votes
5answers
224 views

Does publishing the md5sum of a private key compromise the private key in any meaningful way?

If I have a 4096 DSA private key used for signing binaries, and I want to ensure that a partner has an identical server using the same private key, can I send the md5sum of the private keys over an ...
1
vote
2answers
158 views

Securing communications in decentralized network of servers

Lets consider the following setup: One has a decentralized network of servers. A single root certificate has been distributed to all servers which has been positively checked as authentic and ...
4
votes
2answers
940 views

Is it dangerous to use the same key (RSA) for both encryption (PGP) and authentication (SSH)?

Alice wants to send an encrypted message to Bob, but she also wants to connect to Carol's server. Are there any dangers associated with using the same RSA key for both PGP and SSH (other than a lack ...
1
vote
1answer
970 views

How can i store encryption key into Microsoft provided Key container?

I'm working on an application in which user will enter encryption key via GUI and my app will fetch that encryption key. Now i need to store that received key into Microsoft key container. I got this ...
16
votes
4answers
3k views

Is it dangerous to publicly share ciphertext?

Alice wants to share a message with Bob, but Alice and Bob can never be in the same place at the same time. We can assume they both know each others public keys (or agreed on a shared key, if that ...
-4
votes
1answer
1k views

AES 256 bit key to plaintext conversion? [closed]

I'm a little rusty on cryptography, but I have successfully acquired a 256 bit key that is used for encryption and I want to know if it is possible to reverse it into its corresponding plain text ...
2
votes
0answers
635 views

Which keys does a bank typically exchange with a card scheme?

I'm trying to understand the different EMV-related keys that are shared between a bank who issues EMV cards and a card scheme, such as Visa or MasterCard. I understand the bank would typically ...
5
votes
2answers
1k views

Continued Use of Kerberos

I posted this question over on Crypto.SE, but didn't get any takers and thought it might be more suited for this site as it were, so I'm cross posting it here. I was recently looking through the Mac ...
6
votes
5answers
2k views

Bastion host that allows jailed users to SSH but protects private key

Basically, I'm trying to let the user use a private key without having read access to it. Use case: Employee needs to SSH to a server in the data center. There is 1 private key for all servers, ...
1
vote
0answers
772 views

Storing private messages in a database

I am creating a portal where users can send private messages (PMs) for a very large audience. So I want to encrypt the messages and store them in the database. But I do not want to ask the users for ...
4
votes
1answer
262 views

Recommended symmetric key usage period

Let's assume that there are two nodes A and B connected over a network. Both have a single pre-shared symmetric key (e.g., AES-128) and exchange messages. What is the recommended period, until the ...
2
votes
2answers
401 views

Using 1-day expiration GPG keys only… any disadvantages?

From the thread Does OpenPGP key expiration add to security? , we know that the faster the keys expire, the greater our security. The minimum expiration for a GPG key seems to be 1 day. Thus, isn't it ...
-2
votes
3answers
260 views

Is this adaptation of using a One Time Pad safe?

For example, lets say there are two people named, Bob, and Jim. Bob wants to send Jim a long secret message, and he decides to use a OTP to encrypt his message. Both Bob and Jim know a secret ...
47
votes
2answers
14k views

Criteria for Selecting an HSM

A very sensitive application has to protect several different forms of data, such as passwords, credit cards, and secret documents - and encryption keys, of course. As an alternative to developing a ...
8
votes
2answers
540 views

Backup schedule for Encryption Keys

How often should encryption keys be backed up? Should this be done on the same schedule as the encrypted content/configuration? That seems excessive, as the keys do not change as often. Perhaps ...
7
votes
1answer
17k views

Exchange of DEK and KEK (encryption keys) between app server and key server

In my application, it is required to encrypt a user's data before inserting it into the mysql database. I am using AES algorithm to encrypt the data using a 256 bit hash (and is calling it Data ...
6
votes
4answers
3k views

SSH: reusing public keys and known-man-in-the-middle

Usually, people recommend to use a single private-public key pair everywhere (if we're not talking about a possibility of compromising the private key): Best Practice: “One per-user ssh key” or “...
9
votes
3answers
2k views

AES using derived keys / IVs. Does it introduce a weakness?

I'm looking for an efficient way to encrypt multiple fields in a database with AES using a single global key, used throughout a large web application. Obviously in order to re-use this key, a unique ...
3
votes
4answers
2k views

Asymmetric crypto: Decrypt own messages without having private key

I have built a messages system for my website. Users can send the admin messages which are stored in the DB after being AES-encrypted. I think that using asymmetric crypto (RSA through openssl) ...
13
votes
3answers
19k views

What is the DUKPT Key Derivation Function?

I'm tasked with decrypting ciphertext acquired from an encrypted card reader. The card reader utilizes DUKPT(derived unique key per transaction) scheme and 3DES encryption. I don't have a problem with ...
29
votes
4answers
6k views

How can PrivateSky not see your data?

PrivateSky is a website that promises encrypted "cloud-like" secure information exchange. They promise that except the sender and receiver, nobody can see your data. After testing it yesterday, I do ...
8
votes
1answer
7k views

Storage of 'secrets', keystores, HSMs and the rest

I've been digging for the past few days into storage of sentitive data. If I store this data in a database, I believe the general accepted practice is to store sensitive data encrypted, for various ...