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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2
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2answers
100 views

How to know when an OpenSSH rekey occured, and how to trigger one?

I have a twofold question about OpenSSH rekeying. I use OpenSSH 6.4 on the server side and the connection between client and server is a SSH2 connection. The questions: How do I know when a rekey ...
-1
votes
1answer
155 views

CRC-96(ZIP) decryption

Is there a way to decrypt CRC-96 encrypted string? I am testing a web application which stores the password in the database in CRC-96 encrypted format.
7
votes
5answers
205 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 ...
-5
votes
1answer
82 views

What is AES 256 bit encryption? [closed]

I was looking through some apps to store my passwords in on the App Store when I found one that boasted an "AES 256 bit encryption system". Now that sounds all very good and well, but that doesn't ...
5
votes
3answers
71 views

Asymmetric encryption and signature performed by hand

There are some methods of encryption so easy that you can do them be hand, but is there an easy(ish) method of private & public cryptography and signing that a human can perform it by hand? The ...
5
votes
3answers
129 views

Encrypt Items With Single Key or Use KDF+Salt To Encrypt Each Item?

I'm currently planning the development of a system where extremely sensitive information for individual users would be stored. There are currently two approaches being discussed. In order to make it ...
0
votes
1answer
32 views

Hashing and signing partial data in payload

I'm hashing and signing part of a payload prior to HTTP Posting from a mobile device to server side. The payload contains of about 7 data elements and only 3 of them are hashed/signed using a private ...
1
vote
1answer
83 views

Client-side encryption using public-key

My situation: Login password from a POST request is left in browser memory in clear text as long as cache is not cleared (manually/closing browser). Connection is HTTPS. Possible Solution: ...
1
vote
1answer
107 views

AES step by step

I can't seem to find an AES tutorial that starts from Unicode to Cipher text. All of the tutorials I found starts with 128 bit block already. Also, where do I start or what topics do I have to start ...
3
votes
2answers
170 views

How difficult is it to brute-force Windows EFS encryption?

With EFS I have C:\$USER\ encrypted so all files owned and used by said user are encrypted. If this laptop is stolen, am I correct that they could pull the microsoft user password hashes, crack them,...
22
votes
3answers
16k views

Encryption and compression of Data

If we want both encryption and compression during transmission then what will be the most preferable order. Encrypt then compress Compress then encrypt
0
votes
1answer
33 views

AES-CTR with PBKDF2 for IV for file archiving at server. Is this ok?

I have tried to grasp enough of encryption/hashing to be able to implement a secure storage for files, server side. Once I have it down to reasonably safe I'll go over it with an expert. There is no ...
3
votes
1answer
166 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 ...
3
votes
4answers
167 views

How can a network be secured against attacks coming from the inside?

(updated to (hopefully) be less broad) No matter how well one secures a network there's always the chance of an attacker gaining access. In a shared home + home office network (eg. for a remote ...
1
vote
1answer
59 views

How to test TLS handshake process?

I need to test the handshake process of TLS. I thought to use inter-process communication in Linux. Is it possible or not? If not, what simulator could be used for this purpose? If yes, what do I ...
3
votes
2answers
1k views

How to store an encryption key on shared hosting?

I am designing a simple online patient management system that is running on shared hosting. According to national regulation sensitive data should be encrypted when used online, so I have encrypted ...
0
votes
1answer
73 views

What's Google Inbox request/response obfuscation skill? [closed]

I Inspected Google Inbox network resources via Chrome Developer Tool. I saw some request/response payload and result. This object type is not readable for human. I've never seen this kind of ...
39
votes
2answers
31k views

Where to store a key for encryption?

I am looking for a way to store a key used for password encryption. I am using a MySQL database which would store a user name and a password encrypted with AES_ENCRYPT(str,key_str). Where can I safely ...
1
vote
0answers
59 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?
3
votes
1answer
75 views

Creating accounts on sites with no security?

I'm sort of confused about security on some sites. Here on stackexchange.com, for example, seem to have no security normaly, but as you log in or create an account, it uses keyexchange and an ...
1
vote
0answers
31 views

Client Side Encryption (CSE) across multiple clients

Working on 2 layer security in the cloud (AWS). Have multiple clients pushing files to S3 document storage which are then retrieved by one EC2 instance. Multiple external customers each requiring ...
0
votes
0answers
87 views

Should I blur the cached snapshot of my app?

I recently ran a security scan on one of my iOS apps that suggested I modify my apps display as it enters the background so that the screenshot stored in the cache does not expose any sensitive data. ...
6
votes
1answer
264 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 ...
2
votes
1answer
196 views

What kind of encryption or obfuscation is this? [closed]

I found this script on a web page who attempted to change my router's DNS configuration. But I can't understant what kind of encryption or obfuscation is used. Here, a sample of the code on the page:...
1
vote
2answers
76 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 : ...
1
vote
0answers
14 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
votes
0answers
75 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
votes
1answer
41 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 ...
-6
votes
6answers
195 views

Relative merits and risks of encryption and OS security [closed]

There are many aspects to computer security and many threats to address: poisoned DNS, worms, trojans, viruses, rootkits, firmware malware, etc. One of the biggest software vulnerabilities is buffer ...
2
votes
4answers
4k views

Understanding AirCrack output in Backtrack 5

First let me clarify that I was trying to crack WPA2 in my home for educational purposes. I followed some tutorials and the message I received was: key found! [ilovegod] I know that this is not ...
5
votes
1answer
116 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 ...
3
votes
2answers
155 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 ...
0
votes
1answer
61 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 ...
0
votes
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
50
votes
2answers
7k 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 service?...
1
vote
0answers
38 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. ...
21
votes
1answer
936 views

Linux, TRESOR and XTS

I want to switch from using LUKS for full disk encryption to TRESOR. TRESOR tries to prevent cold boot attacks by storing the encryption key in the CPU's registers. It uses the kernel's crypto API for ...
1
vote
1answer
203 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 ...
0
votes
1answer
78 views

BBM pin to pin security

If a BBM message is intercepted over unsecure Wi-Fi and the PIN of the intended recepient is known. Can it be decrypted easily.
5
votes
4answers
305 views

Avoiding direct object references

Say I wanted to avoid exposing a database primary key in a URL; somehow I must encrypt the key, so that the url only exposes elements of an unenumerable cipherspace. What kind of encryption should I ...
15
votes
1answer
4k 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 ...
4
votes
2answers
409 views

What data is not encrypted in iOS 8+ when “locked”

Scenario: iPhone 5+ with iOS 8+ with system encryption enabled. The phone is on and locked. (the user has authenticated (unlocked phone) at least once since power-up, and then relocked). What data/...
1
vote
1answer
43 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
75 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 ...
0
votes
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 ...
-3
votes
2answers
115 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 ...
9
votes
1answer
250 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 ...
1
vote
0answers
59 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 ...
9
votes
3answers
405 views

Linux Plausibly Deniable File System

Is there any way to encrypt a linux filesystem in such a way to maintain plausible deniability? E.g. "Hidden OS support," the way Truecrypt and Veracrypt work, they only support Windows OS due to low ...
4
votes
2answers
844 views

How secure is AES-256-CBC with user provided password and initialization vector

From my understanding the IV is used as a previous block for the first block only. But since each block is used by the following this adds significant security is a IV is provided and not based on the ...