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

learn more… | top users | synonyms

3
votes
1answer
105 views

how do we encrypt 100bits of plain text to get 100bits cypher text using DES?

We have a scenario like that we need to encrypt 100 bits of plain text using encryption algorithm like DES (algorithm takes 64bits plain text block and generate 64 bits of cypher text block, key using ...
2
votes
2answers
211 views

Is it okay if passphrases to KDFs are “predictable”

I'm looking to do file encryption for small amounts of text (8-100 characters for each item being encrypted). Here's what I have: A secret passphrase and a salt. I Use Rijndael to generate a key and ...
2
votes
1answer
93 views

Are TLS session keys cached in a browser?

For example, when authenticating to a TLS protected service, and then closing the tab, you can sometimes reconnect to the service afterwards without re-authenticating. In preservation of perfect ...
6
votes
2answers
141 views

Decrypting arbitrary offset of encrypted file

I want to store encrypted files on some storage backend that allows me to fetch bytes X through Y of the encrypted file. I can obviously decrypt the entire file locally and send it back to the client. ...
3
votes
3answers
142 views

How do browsers negotiate SSL/TLS connection parameters?

For the purpose of this question, let assume that an SSL/TLS connection has 4 parameters: protocol, symmetric encryption method, asymmetric encryption method, MAC. During the negotiation of SSL ...
37
votes
9answers
5k views

Is full disk encryption on a server in a secure data center pointless?

I am having a debate with several people regarding how much protection full disk encryption provides. dm-crypt is being used to encrypt data which is required by my company to be encrypted at rest. ...
-4
votes
1answer
114 views

Is it possible for someone to read Gmail messages with a man in the middle? [duplicate]

Assuming these hypotheses: 1) Your account isn't hacked (hacker has not entered your account directly) 2) Gmail encrypts via SSL end-to-end 3) The hacker is not Gmail or Google 4) There is no ...
12
votes
4answers
2k views

How can I decrypt my files from “Cryptowall” encryption? [duplicate]

I just got infected with "Crypt0L0cker" malware,virus or whatever that might be. They gave me a link (http://bica3zjnvl6fxkqf.tor-area.org/jrrk14.php?%20user_code=94aya99&user_pass=2616, the ...
2
votes
2answers
61 views

Authenticated encryption (Symmetric encryption) for .NET applications [closed]

Is there an implementation of Authenticated encryption for .NET applications? The AES API from .NET does not include mode such as GCM. In the documentation, I can only see insecure modes (ECB, CBC, ...
4
votes
2answers
397 views

Why is Chrome saying that “TLS_RSA_WITH_AES_128_CBC_SHA (0x2f)” is an obsolete cipher suite?

When I go to this site, Chrome Version 44.0.2403.89 is connecting to the server with TLS_RSA_WITH_AES_128_CBC_SHA (0x2f), and it states that this is an "obsolete cipher suite". For what reason is it ...
7
votes
1answer
257 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 ...
1
vote
0answers
48 views

Can high network usage be detected and prevented in Tor? [closed]

I've already asked this question here but as of yet it has no views/answers. I was wondering if there is any way for Tor to detect high network usage in the context of transferring large files using ...
3
votes
2answers
86 views

Can you use ssh for secure inter app communication on the same device?

I use ssh to get an encrypted connection between servers and local machines all the time. It's fast, it's secure, and there's a way to do it in nearly every system programming language that I've used ...
23
votes
1answer
760 views

How to encrypt in PHP, properly?

How do I encrypt data in PHP, properly, using symmetric-key encryption? I have a message M and a secret S. I'm looking for a solution that uses cryptography properly without making any of the usual ...
1
vote
0answers
54 views

Biometric device instead of password - signature security

Lets assume that there is a biometric algorithm for user authentication which compares fingerprints with an user's signature saved in database (comparing function is not important here). Next there is ...
0
votes
2answers
76 views

Random characters and letters form obsfuscation

I know that this question has been asked many times, but would JavaScript encryption work if I just added 100 random numbers and letters to the password? That would be hard to reverse engineer, ...
0
votes
2answers
78 views

Do modern cryptographers / cryptoanalytics need the knowledge of historical cryptography

It makes a lot of sense for people to know the history of their profession from various points of view and I suppose especially in cryptography because people can still use old ciphers and no one ...
-2
votes
1answer
45 views

Attack on Androids Encryption called FROST

http://www.extremetech.com/computing/150536-how-to-bypass-an-android-smartphones-encryption-and-security-put-it-in-the-freezer I read this article about FROST and in the comments someone was stating ...
-1
votes
1answer
62 views

Best way to store client side Encryption keys

I have different client applications running on different OS (iOS, Android, Windows Desktop, Windows Phone, Mac, Windows Store -All Native Apps-) I have to decrypt (AES-128) some files (thousands of ...
2
votes
1answer
63 views

Encryption of settings/credentials in mobile apps - what threats does this protect against?

I have been decompiling Android apps recently. In a sample of 37 apps, 12 of these use some form of custom encryption/obfuscation to store settings and credentials on the device. By necessity, the ...
62
votes
7answers
18k views

How hard is it to intercept SMS (two-factor authentication)?

A lot of two-factor authentication mechanisms use SMS to deliver single-use passphrase to the user. So how secure is it? Is it hard to intercept the SMS message containing the passphrase? Do mobile ...
1
vote
1answer
69 views

Secure Software Architecture

I am designing a software architecture and i need some suggestion and clarification on few issues. This will be a server side RESTfull API for accessing data and multiple mobile/desktop client to ...
-2
votes
2answers
184 views

Cryptowall encryption files

This is a question concerning the way the Cryptowall ransomware encrypts files on the victim's computer. Someone knows if it is possible to recover the encryption key comparing the encrypted file and ...
1
vote
0answers
47 views

Is there anything to worry about — worth putting security on a simple test site?

So I want to make a site, this site won't have users (so no one but me will be able to post to the site) or anything it will just echo out items from Mysql like title and text-body I was wondering if ...
0
votes
2answers
68 views

Content on a usb flash drive available for a limited time [closed]

I need to distribute some content on a USB flash drive. This content should be available for a limited time only. I am looking for some approach to achieve above. So far I do not have information ...
12
votes
6answers
5k views

Is (safe) encryption over compromised line impossible?

I realize something like this would be the holy grail of communications security and have never heard anything to suggest it has been done. Am just wondering. A lot of mathematicians and computer ...
4
votes
1answer
161 views

Securing administration network

We would like to secure our administration network from advanced persistant threats and also from rogue administrators. I have already read the best practices from SANS Institute, NSA or other guides. ...
4
votes
2answers
86 views

What encryption and signature systems (don't?) allow for plausible deniability of the OP's key being used?

I need to prevent Mallory from blindly matching encryption and signing keys to messages Hypothetical scenario: A user creates a public key An encrypted or signed payload exists. With only public ...
1
vote
2answers
106 views

Could I ever be legally required to decrpyt user information? [closed]

Suppose I host some web app which stores information about its users. In the interest of confidentiality, that information is stored in an encrypted format. Under what circumstances could a legal ...
3
votes
4answers
146 views

How safe is password based key derivation in the case of long password?

I am encrypting files inside a device and store it. So I need to maintain the same key throughout the life cycle of the device. For key derivation I use EVP_bytestokey() of OpenSSL. The problem in ...
0
votes
1answer
84 views

I need to transfer user's private key (RSA) to my App. Is file sharing a good solution?

I've asked a similar question here earlier iOS: Is it ok to store a RSA private key (use to decrypt text) in your application document directory? However, the person recommend me to use keychain ...
1
vote
1answer
45 views

Key derivation inside secure container of HSM

I have to implement custom key derivation function which basically works as follows: I have encryption key K in secure container of HSM. K can't be exported and the only way how to use it is through ...
3
votes
1answer
53 views

Cipher usage by end users and browsers

How do I check in apache logs as to what cipher end users / browsers are using ? Are there other tools to achieve the same to get a result in percentage ? related link: How can I determine the ...
4
votes
1answer
153 views

Sending Encrypted Messages with Hybrid RSA, AES and HMAC SHA-256

Is this a Secure strategy for sending a large Encrypted Message using Hybrid RSA 2048, AES 256 and authenticated with HMAC SHA-256: Given the Alice already has Bob's RSA Public Key, Alice: ...
-3
votes
1answer
43 views

A collection of tests and demos for security headers and TLS configurations [closed]

There are (or have been) various websites designed to educate and provide examples on good / bad configurations of security headers and TLS configurations (e.g. https://badssl.com/) I want to build a ...
9
votes
1answer
114 views

How to make sure that the cryptographic hardware accelerator is being used in am335x?

I want to use the AES hardware accelerator in am335x. I was able to generate the cryptodev.ko and cryptosoft.ko drivers. From my application program I am making use of openssl apis in CBC mode, and I ...
3
votes
1answer
118 views

Can applying second cipher (including home brew) reduce security

I have asked a question regarding the benefits (if any) of the following scheme: AES(HomeBrew(plaintext)). There are many good answers for that, but many people say that it's theoretically possible ...
10
votes
8answers
1k views

Double encryption with home brew algorithm

Everyone says that home brew encryption is not a good idea because one day the algorithm will be known to attacker which sounds reasonable. So that seems it's main problem, on the other hand known ...
0
votes
0answers
87 views

How can secure email be used while avoiding government attention?

Presumably all unencrypted email is available to federal agencies including IP addresses, header information, and email content (eg, through SMTP with or without SSL and TLS -- thunderbird has an ...
14
votes
2answers
2k views

How would I implement “Broadcast Encryption”?

I have a stream that I want to encrypt for broadcast to 10,000 subscribers. I know I should encrypt this data using a symmetric key; and also intend that this symmetric key will be rotated every 30 ...
0
votes
1answer
85 views

Is this data encryption process secure?

I have created the following encryption process which I will be using to store CD keys inside my database. Before I use it, however, I need to make sure that this is as secure as possible. From what ...
9
votes
2answers
260 views

How secure is “Firefox Hello”?

The new "Firefox Hello" feature promises easy and safe video conversation. It is not nescessary to create an account, you simply share a link with your partner to start the conversation. The ...
22
votes
2answers
45k views

Security comparsion of 3DES and AES

Which one is more secure and least possible to be broken through cryptanalysis AES or 3DES (no matter performance)? I need to use encryption for my projects to store and secure sensitive information ...
2
votes
1answer
132 views

if a public key cannot decrypt the cipher text, then how can a private key?

I understand the "public" part of public key cryptography. Not the "private" part. For example, let's say our public key is %7 (modulo 7). And the message to be encrypted is 22. And we know that 22 ...
1
vote
1answer
73 views

Basic XOR cipher for longer messages

How much effective strength is the following adding to a basic 512 bit XOR cipher? Private Key = Key0 consists of 512 randomly generated bits. This key is never used to encrypt or decrypt anything. ...
1
vote
1answer
57 views

Are encryption algorithms designed to hinder parallelization?

Are things like large memory requirements and constantly mutable state typically added to encryption alogrithms to hinder the ability of attackers to try multiple candidate keys simultaneously? Also, ...
3
votes
1answer
53 views

In postgres LDAP authentication, are passwords encrypted?

I am wondering if postgres LDAP login is secure? Would passwords be transmitted in clear text potentially if this is not set up properly?
15
votes
3answers
16k views

Is RedPhone a secure and secret way to communicate?

RedPhone provides end-to-end encryption for your calls, securing your conversations so that nobody can listen in. But really, how is the probability that a voice conversation is wiretapped still? ...
-1
votes
2answers
59 views

What are the advantages in using LUKS + hardware encryption on SSD?

I can't see what the advantages might be, but I think this would slow data transfer down while providing no extra protection. Am I right or am I overlooking something?
4
votes
2answers
237 views

Does adding a non-entropic part to a password makes it less secure?

Suppose I'm encrypting a file via AES using a password of my choice, or creating a TrueCrypt volume using a password and no keyfiles. Which of the following two passwords would be more secure: ...