Encryption is the process of transforming plaintext using a cipher to make it unreadable to anyone except those possessing the key.

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95 views

Is it possible to to encrypt multiple messages with multiple keys and get only one cipher?

I want to have cipher which when people decrypt it with their own key, get different meaningful messages. Is this possible at all?
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1answer
250 views

Are RSA Key Pairs unique?

I generate RSA key pairs mostly using the following command: ssh-keygen -t rsa -b 4096 -C "someemail@hostname.com" which produces a public-private RSA key pair. If I run this command again and ...
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0answers
57 views

Key Hierarchy and key Encryption

If i have two 56-bit DES keys, and I use these two key to encrypt a 256-bit AES key. Like this: K_AT encrypts K_BT and K_BT encrypts K What is the effective security of key K? Is it 2 X 56 Bits?
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2answers
74 views

Is it possible to find the salt?

I have this PHP code with me : $auth = md5($username.$password.$salt); I have a dummy value : $username = user $password = password And I also have the resulting MD5 Hash : ...
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0answers
13 views

Does windows still use it's software based user keys when TPM-based EFS is enabled?

I have an infineon TPM installed, with ownership taken, and EFS enabled with the TPM taking control of EFS for me. I do know that regular EFS uses the windows user cryptography/login password to ...
0
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0answers
70 views

For multiple clients it's better symmetric or assymetric encryption?

I'm a newbie in the encryption world so I'm here for asking which is the best solution between Symmetric and Asymmetric encryption. In our use cases, we have multiple clients that must be ...
0
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1answer
37 views

Encrypted traffic analysis

If i tunnel any tcp traffic true ssh or any ssl encrypted protocol will some one capturing the traffic capable of do some kind of offline decrypting using the capture file ?? What technic they use to ...
0
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3answers
120 views

Can you NEVER be 100% sure you decrypted a message?

Put in simple terms, for most encryption algorithms: can't you technically ever be sure you actually decrypted something? Sure, if you decrypted a word document and MS Word can open it you've got a ...
5
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1answer
104 views

Wasn't WhatsApp messages already encrypted?

According to this article, which was written in 2014, WhatsApp had partnered with Open Whisper System to make its (text based) messages encrypted. So what's the big change now that Whatsapp's ...
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0answers
25 views

Cryptography and key exchange [duplicate]

Can someone please explain the Diffie-Hellman key exchange for me. I have been studying it but I don't actually get the concept
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5answers
192 views

Secure application data transmission via SMS channel

There are mobile banking applications that use SMS channel to communicate with their server. Some of them offer both internet and sms channels which the customer gets to choose from. While there's ...
0
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1answer
50 views

Difference between Hybrid encryption and Diffie-Hellman key agreement?

Can someone explain me the difference between the Diffie-Hellman key agreement (DH encryption) and Hybrid encryption? As to my knowledge DH key agreement uses public and private keys to generate a ...
3
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2answers
151 views

Is it safe to reveal AES encrypted password?

Please correct me if any of my statement is incorrect. It is probably more good practice to not show any hint of the password. However, AES encrypted passwords by itself cannot be used to decrypt ...
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0answers
34 views

Migration problem between different machines using TrouSerS TPM library

My question coincides with the question posted by Maximiliano Ezequiel. Below is a question. I could make migration process work in one single machine. I can: Export SRK public key. ...
1
vote
1answer
101 views

How to disable weak cipher suits in java application server for ssl

I have a custom Java application server running. I am seeing that there are some weak cipher suites supported by the server, for example some 112-bit ciphers. I want to disable those. Where can I do ...
3
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1answer
143 views

Does the use of JavaScript make ProtonMail insecure?

I like the look of ProtonMail. However, what has stopped me from signing up is that JavaScript seems to be used at various points in the site, and for someone to read your email they must click on a ...
14
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1answer
3k views

Which Cryptography algorithm is used in WhatsApp end-to-end security?

I have a presentation to make on Social Network Security. I have been doing some research regarding this. I did a lot of searching, but was unable to find the Crypto Algorithm used by WhatsApp for ...
1
vote
1answer
40 views

Getting file from Amazon s3 encrypted based on user

I am storing my files on Amazon S3. My problem is that whenever a user asks for a file I want to generate an encryption key (user specific key) and encrypt the file and send it to him. So basically I ...
3
votes
1answer
70 views

Is having a unique key to encrypt data not sufficient

Is it necessary to use a unique Initialization Vector (IV) with various cipher modes of operation (e.g. CBC) even though I use a unique key to encrypt plain text every time? It is said that an IV ...
9
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1answer
217 views

Why is whatsapp Inc. still caching user data even after introducing the end to end encryption?

Last week Whatsapp introduced the end to end encryption to prevent man in the middle intercept/attack. The company claims that the data such as text, call, video, images and documents are stored ...
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2answers
113 views

Is it more secure to delete emails from the server once a client has downloaded them?

From this email provider We strongly adivse people to download their email whenever possible, so as to lessen the amount of personal private data present at any time on the servers. Does ...
1
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0answers
47 views

Data recovery from BitLocker encrypted device that has been quick-formatted

I apologize if this is in the wrong place, but I couldn't find anywhere else that seemed appropriate for these questions. My classmate has a 512GB USB drive that he had formatted as exFAT and ...
0
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1answer
93 views

Does non-persistent data ever need to be encrypted?

Does non-persistent data ever need to be encrypted? If I had a project with confidential data stored in non-persistent class variables should I be doing anything to protect this data? I am developing ...
2
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1answer
145 views

Open source WhatsApp client [closed]

As a follow up to Whatsapp encryption keys discussion and from WhatsApp security whitepaper, it seems that most of the components to a fully secure end-to-end encryption are already there but what ...
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2answers
94 views

Idea for an encrypted pastebin NON-web application

I have an idea for an app that might be useful (though if it isn't, I've still learned in the process, which is what matters). There are a bunch of encrypted pastebin web apps out there (e.g. ...
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1answer
64 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, ...
3
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1answer
58 views

Is this good/secure method for client-server communication encryption?

Something came to my mind, and I wonder if this is proper method for client-server communication, and if this method is wide-used. On connection, client generates seed, encrypts it using asymmetric ...
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2answers
369 views

How does WhatsApp's new group chat protocol work and what security properties does it have?

By now everybody has noticed that WhatsApp rolled out full end-to-end encryption recently, for direct communication, for media attachments and for group chats. I've read their white-paper (PDF) and ...
50
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2answers
6k views

How is WhatsApp sending end-to-end encrypted messages in push notifications?

WhatsApp implemented end-to-end encryption (whitepaper) in their latest update. How is it possible for WhatsApp to send push notifications with message contents to the Apple Push Notification ...
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2answers
793 views

WhatsApp end-to-end encryption verification [closed]

IS there any way to verify the encryption from remote or so? Like my friend is 1000 miles away from me the physically QR Code scanning is not possible. So is there any way to verify the same?
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1answer
46 views

Break encryption by applying accidental-overwrite techniques

I read that there are ways, at least on mechanical drives, to sometimes recover data that was overwritten (not just deleted). Now I was wondering if it was theoretically possible to break a fresh ...
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1answer
1k views

End-to-end WhatsApp vs Telegram [closed]

What do you think about the latest WhatsApp update? Is now WhatsApp as secure as Telegram? Which one should be trusted? Which one has the strongest and most secure encryption?
14
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1answer
449 views

How would one verify that the public key from WhatsApp's servers belongs to the person I expect it to?

WhatsApp had recently announced end-to-end encryption on all communications. While that's an impressive move, I still have a big open question mark. The articles and this white paper suggest that the ...
1
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0answers
137 views

WhatsApp end-to-end encryption for all devices [closed]

The news is out, WhatsApp switched on encryption for a billion people. It supports all devices and encrypts texts, photos, videos and calls. There are so many questions that just came to my mind ...
3
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1answer
63 views

Is appending plaintext to salt equally safe as appending salt to plaintext

Is using hash(salt, plaintext) equally secure as using hash(plaintext, salt), i.e. can the plain text be appended to salt in place of appending salt to the plain text. Why or Why not? What kind of ...
4
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2answers
79 views

Does EMV protect against sniffing PAN data from untrusted network?

I have received conflicting information in regards to the security of PAN data on the wire. Can this be sniffed with properly configured EMV at an atm? To quote from the link below: ...
1
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1answer
72 views

Stronger Password-based File Encryption on OS X [closed]

I am wondering if there are any better alternatives than the zip command on the OS X terminal. My intention is to add a password to a compressed file. I have been using: zip -j -e -pMY_SECRET ...
2
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2answers
154 views

Is the RSA private key useless without the password?

I notice whenever I generate a new gpg key (using pgp) I always have to assign a password to it, which makes perfect sense. But if I'm not mistaken, gpg is based on prime numbers. How is this ...
5
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2answers
142 views

Does TLS authentication encrypt username as well as password?

I connect to my VPN provider using openVPN. The server uses a combination of username / password and TLS authentication. If I am on a public wifi and connecting to my VPN, is my username encrypted? ...
0
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1answer
40 views

Encrypt existing SSH key

I've created an RSA keypair for ssh access to a remote server. This all works. When creating the keypair, I didn't enter a password. Now I would like to encrypt the key, secure it with a password. Is ...
0
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1answer
33 views

Why is calculating the checksum of an IP Datagram header and then encrypting it not appropriate to provide Data Origin Authentication?

So assuming Alice and Bob have agreed to use a particular symmetric cryptosystem and share an appropriate key, they want to achieve data origin authentication by computing the header checksum of an IP ...
3
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5answers
611 views

Why can passwords be used to encrypt data, but are less strong for authentication?

Encryption software is often password based. Even if the adversary gets your computer they can't get the data without knowing the password, and bruteforcing is infeasible. Websites use passwords to ...
2
votes
2answers
54 views

How does GnuPG encrypt secret keys?

When creating a secret key with GnuPG, you are asked for a password to protect it. Which encryption algorithm is used to achieve this? The handbook only says that a symmetric encryption algorithm is ...
4
votes
2answers
53 views

How to check and trust call encryption software

There are lots of software for mobile operating systems providing end-to-end encryption. What is the best way to decide which one is trustworthy if their source is not revealed? Reverse engineering ...
11
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2answers
647 views

Replay attacks and PGP email encryption

From my understanding of PGP email, the following is possible: Alice sends a message to Bob. Then Bob can take that exact same message and send to Carol while making it seem to Carol like it is from ...
6
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3answers
142 views

Android full disk encryption

I am using Android 4.4.4. There is an option called phone storage encryption. From what I have read the crypto is secure. However, I read this article which said Google is able to reset passwords: ...
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1answer
83 views

Public key encryption for initial challenge-repsonse

I understand public key encryption, public key authentication, how digital signatures work and challenge-response authentication, but what confuses me is when they are all combined, and the question ...
0
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1answer
28 views

Veracrypt options to protect against multiple versions of an encrypted volume

I'm planning to use rsnapshot to backup a veracrypt volume as it changes. This means I will have multiple versions of the same volume, with slight differences in data. It is my understanding that ...
7
votes
1answer
87 views

What's the most secure way to circumvent encryption to enable password recovery?

I have a web app (which I've talked about here before). Users can use it to save people's contact details. These contact details are encrypted to ensure that they are difficult to get at if they're ...
3
votes
1answer
56 views

OpenSSL's EVP functions, more specifically EVP_SealInit

Reference: https://wiki.openssl.org/index.php/Manual:EVP_SealInit%283%29 I want to securely share a symmetrical key between two endpoints using OpenSSL's EVP interface. Transferring the encrypted ...