Questions tagged [password-based-encryption]

Encryption using a key derived from a password or passphrase entered by the user.

Filter by
Sorted by
Tagged with
1
vote
1answer
19 views

Am I using these key derivation functions correctly?

I am a bit confused about key derivation functions. I am trying to use the argon2 KDF from the passlib python module to do the ...
1
vote
1answer
246 views

Hardware, Handheld Password Manager

I am currently working on a hardware project that will utilize the native USB and keyboard emulation capabilities of the Teensy device. Essentially, the user will store an encrypted password database ...
1
vote
0answers
63 views

How to encrypt a text file in a portable manner based solely on a password?

I used to use openssl aes-256-cbc, but the problem I have with this is when I try to decrypt in a different version of the distro it fails, as if it depends also on some internal key or something, ...
0
votes
1answer
155 views

Best practise for encryption in a password manager

I'm trying to make a password manager for Windows installed computers, and after researching the best ways to encrypt the passwords in the database (I'm new to cryptography) I think I've come up with ...
4
votes
1answer
152 views

Security limits of password-based encryption

A reasonable way to do password-based encryption is: put the passphrase¹ and nonce in a well-parametrized memory-hard iterated hash function like Argon2, to derive a key 128-bit or larger. output the ...
126
votes
5answers
112k views

What is a cryptographic “salt”?

I'm a beginner to cryptography and looking to understand in very simple terms what a cryptographic "salt" is, when I might need to use it, and why I should or should not use it. Can I get a ...
0
votes
1answer
62 views

Making a secure file sharing scheme usable

I am trying to realize a secure file sharing scheme based on asymmetric crypto. Users will access this via browser. In short, it works like this: Users register and set their username and password. ...
6
votes
2answers
2k views

How are recovery keys possible if something is encrypted using a password?

I thought that encryption works as follows - it is about changing the thing we want to secure using an algorithm and using the password to mathematically change the secured content so it is unreadable....
2
votes
1answer
62 views

Encrypting data with HMAC-SHA1 challenge response as the key

I came across a piece of software that uses the following algorithm to generate a symmetric encryption key to encrypt data. Generate a non-secret 64 byte random string $M$ (fixed challenge) Generate ...
2
votes
1answer
40 views

End-to-end photo storage

I've been tasked with developing an app that will need to store photos a user takes securely, and I've been struggling to think up a method to do this. What I was thinking so far is as follows: When ...
1
vote
1answer
277 views

How to choose parameters for Argon2 for password vault

I'm creating a password vault and I'm planning on using Argon2id to derive the master key from the master password. For encryption I'm planning on using XChaCha20 with Poly1305. To be clear: a set of ...
5
votes
1answer
152 views

How would quantum computers affect password based encryption?

At first glance: Assuming that the output of the password hashing function is large enough, quantum computers should have no effect on password encryption as on symmetric cryptography in general. Is ...
-1
votes
2answers
2k views

How to validate a PBKDF2 password

I want to encrypt several files correctly with a PBKDF2 generated key (using a password and salt), I am currently doing so but if I enter the wrong password, as expected an exception occurs. Note: ...
4
votes
2answers
2k views

End to end encrypted web chat app with stored messages in database

I am working on a web app with an integrated chat. All chats can only occur between two users - not more, not less. I am very concerned with security, so I would like to encrypt all chat messages with ...
1
vote
1answer
568 views

Which algorithm do you recommend for practical use to generate unique passwords for each website?

So, in my imagination there is this simple algorithm with only one master password, let's say a prime number 'p', which I have to remember. Using only the address of the website and p, the algorithm ...
2
votes
0answers
141 views

For TCG-Opal drives, which password is used to derive KEK?

SEDs use a user password (PIN) to generate KEK by a KDF algorithm. The KEK is then used to encrypt the MEK (where MEK is internally generated in the drive). But TCG-Opal drives have 9 locking-ranges ...
0
votes
1answer
68 views

What are some of the alternatives to password based file encryption?

With the ever increasing risk of attackers compromising password based encryption by brute forcing or guessing passwords, are there alternatives to this traditional scheme of deriving encryption keys ...
1
vote
1answer
43 views

Issue with decrypting self-coded AES

Summary: As a trainee, I got the task to extract encrypted passwords of our external password manager (Zoho Vault) and decrypt them. The documentation regarding how to decrpyt them is...none. I ask ...
0
votes
1answer
69 views

How to provide secure password based encryption with password reset option

I am trying to build website that will encrypt some data for the user using his/her the output of scrypt on it, now the idea is that this schema is not flexible because if the user loose their ...
1
vote
1answer
67 views

Do all forms of symmetric encryption require multiple pieces of information? (nonce, iv, etc)

I'm attempting to learn encryption and have a very basic grasp of it, but I have questions. First, I'm looking to use AES. I want to take text, encrypt it with AES using a variable-length key, and ...
1
vote
0answers
3k views

Relation between Zoom id,password and join URL [closed]

We all are using zoom application for joining/hosting meetings in this corona virus period. As we create a meeting, a new id, password and a url is generated. Some real examples follow- Id: ...
1
vote
1answer
116 views

Do all PAKE assume that all parties already have a password?

I was looking for a means to perform a key exchange without relying on a PKI. I discovered Password Authenticated Key Exchange (PAKE) and after reading J-PAKE; I have the following questions: Do PAKE ...
0
votes
0answers
51 views

Can a duplicate ssh private key be dangerous?

For convenience I had an id_rsa keypair and duplicated them with a new name. I may or may not use them consistently on different machines. (The reason was to keep an existing id_rsa on a machine I ...
0
votes
0answers
106 views

WPA/WPA password algorithm

I would like to understand the mechanism behind wpa/wpa2 algorithm. Is there any script that can put this theory:(Key = PBKDF2(HMAC−SHA1, passphrase, ssid, 4096, 256)) into action to test it ? I made ...
2
votes
1answer
97 views

In veracrypt when i generate a random keyfile, does the size of the keyfile mean anything?

thanks for looking at my question, i have been getting several different answers to this question so i thought i might ask it here, when i create a random generated keyfile in veracrypt, does the size ...
0
votes
1answer
82 views

Using encryption as authentication

I am building an app in which I would like to encrypt user data and support offline login. From this answer about using passwords for encryption: Best practice is to use a PBKDF to generate a 'key ...
2
votes
5answers
226 views

How passwords are fed to key derivation functions?

Suppose I want to encrypt data, send it over the network, and decrypt it on the receiver side. I know the elegant way to do this is by using a symmetric key to encrypt the data and an asymmetric key ...
19
votes
2answers
857 views

Is there any SRP-like key exchange only using “standard” cryptographic primitives?

I am looking into PAKEs (password-authenticated key exchanges), and it seems like SRP (Secure Remote Password) is essentially the de-facto standard. However, implementing SRP actually requires doing ...
1
vote
1answer
581 views

Argon2 or scrypt instead of PBKDF2 with AES

Is using scrypt or argon2 a better key stretching technique with AES compared to PBKDF2 or bcrypt with regards to a quantum computer brute force attack. The brute force attack I'm referring to is ...
1
vote
1answer
86 views

Simple proof of ownership of a password

I want to do a completely serverless p2p chat application on web browsers, so it won't even have a database to store accounts, but I still want to have some kind of identity system on it (an user can ...
14
votes
2answers
1k views

How to derive two keys from one password

What is the best way to generate two independent symmetric keys from one user-entered password or passphrase? Would using both scrypt and pbkdf2 achieve this?
1
vote
1answer
662 views

Why use PBKDF2 over SHA-512 to derive AES encryption key? [duplicate]

Suppose I am using user passwords to derive AES-128-CBC encryption key. This key will be used to encrypt some sensitive data for the user so that even the website owner / operator can not decrypt it. ...
3
votes
1answer
1k views

Database and End-to-End Encryption

I'm currently designing a mobile/desktop application to synchronize some messages or notes. I'm searching for a way to secure it and to avoid letting the server be able to read the messages. My goal ...
2
votes
0answers
105 views

Encrypted ZIP and plain text attack [duplicate]

I have a Zip archive containing a single password-protected file file.txt. The encryption is "ZIP 2.0 Default Encryption" (ZipCrypto). I know what kind of text (...
5
votes
2answers
2k views

Why cryptsetup default KDF is PBKDF2 and not Argon2(id)?

I plan to do a clean install of ArchLinux with Full Disk Encryption (with LUKS) but I'm not sure to understand the default KDF choice (PBKDF2+SHA-256). I didn't manage to find any pieces of evidence ...
4
votes
3answers
996 views

Should we run PBKDF2 for every plaintext to be protected or should we run PBKDF2 only once?

I am going to store secrets from users. The secrets need to be stored confidentially. For this question, I am concerned only with confidentiality (not integrity). Here is how my encryption scheme is: ...
5
votes
0answers
774 views

How safe can PKZIP-compatible encryption be?

PKZIP encryption has been around since 1990, and its decryption is directly supported in most desktop environments (Windows, MacOS, most Linux distros). This makes it one of very few options when ...
1
vote
1answer
40 views

Is PKCS#5 deterministic if both sides use an agreed salt and iteration count

In a system were both sides have access to a common secret, and publicly exchange an iteration count and salt, can a PKCS#5 (Password-based Encryption Standard) algorithm be used to generate a key ...
13
votes
1answer
3k views

When to use Argon2i vs Argon2d vs Argon2id?

I've read the manual, and multiple articles / StackExchange posts about this topic, but still can't decide which implementation of Argon2 is best for my use case. I want to securely encrypt passwords ...
2
votes
2answers
220 views

Mechanism of PBKDF in encryption key generation with passphrase

I want to roughly understand how the mechanism works of generating an encryption key from a passphrase, by which we encrypt a volume or file. I'm familiar with public key encryption, the concept of a ...
0
votes
0answers
69 views

Authenticating without sending password to the server, and store data encrypted with password derived key on server

I am trying to think of a scheme that would allow a user to authenticate to a server, whithout sending the password to the server, and to also derive a symetric key on the client (that also never gets ...
1
vote
2answers
160 views

In SRP, is the client protected from server impersonation?

Assume use of SRP over an otherwise insecure unauthenticated channel where the user running the client side has chosen a password, the user only uses that password with a trusted SRP client software, ...
5
votes
1answer
303 views

Using a non-secure random generator for IV or salt generation

I was just looking at a post on Code Review when I noticed the other answer to the post. While I would agree mostly with the answer, I do however doubt if having a Cryptographically Secure PRNG is ...
3
votes
1answer
4k views

AES-256 password cracking time

My question is kinda simple. I want to use AES-256 encryption to encrypt my backup. Using a password like this: ...
3
votes
1answer
115 views

What is this called: encrypt $X$ with key $E$, decrypt $X$ with key $D$?

I am a software developer interested in developing an application with cryptography. I can explain what I want to accomplish, but I do not know the technical terms for the cryptographic functions I am ...
0
votes
2answers
454 views

Best practices for saving encrypted user data without a database

We are setting up a web application which requires users to submit sensitive data. Since entering all the required data may take a long amount of time, we want to give them the option to save their ...
5
votes
2answers
559 views

Password derived hash to encrypt known plaintext as password check

The title sounds way too adventurous for what it actually is. I am currently building a system which features some encryption. There is already a system in place, which is built after that scheme if ...
2
votes
1answer
135 views

Is it safe to publicly expose PBE-protected PGP secret keys?

I am working on a PGP scheme where a private key is created offline (and in volatile memory) and must be reused on very rare occasions to sign a piece of exportable data. The private key is locked ...
7
votes
2answers
2k views

Argon2 for both password storage and key derivation

Is using Argon2 for both password storage and key derivation secure? I'm planning on using different salt values, of course. The basic concept is something like this: Alice has some secret data ($...
4
votes
0answers
105 views

Upgrading key derivation by adding a XOR with a known value

In general keys for password based key derivation are derived from a password hash such as the old PBKDF2 function or Argon2, possibly followed by another derivation function to derive data and ...