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

10
votes
5answers
13k views

What does “key with length of x bits” mean?

I'd like to know what it means to say "the cryptosystem C uses keys with a length of x bits". I do not understand what the bits length means... doesn't it depend on the encoding? The same word encodes ...
21
votes
4answers
2k 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. ...
63
votes
14answers
9k views

Ensure that a file can only be decrypted after a specific date

Are there any cryptographic schemes/protocols that would allow me to encrypt a file, make it publicly available, but ensure that it can only be decrypted after specific date? I assume it would be ...
0
votes
1answer
81 views

Hidden OS: Decoy OS ≠ Hidden OS?

I wanted to use two different OS then two OS equal in the distinct functions: Hidden OS: Linux Decoy OS: Windows Has how? because what I have read until today were processes done with even OS, I do ...
0
votes
2answers
120 views

Why do I have to use multiple Keys for each direction and purpose?

I'm currently writing an examen about 'Lessons Learned in the IT-Security'. I already found some thing, which shouldn't be done. But right now I'm in trouble finding the reasons why not to do so. ...
3
votes
1answer
188 views

Hashcat, finding out the Hash

I've been searching but I can't seem to find the much information on how to extract hash's from say PDF files or Lotus Notes files that I can then use in Hashcat? I know how to get them for Office ...
3
votes
1answer
42 views

Is it safer to store valuable information on a unsecure client or send the data through the internet?

Background: I'm creating a secure web app with the purpose to act as a no-knowledge storage for small data (we're talking a few bytes). Since all the encryption and decryption happens client-side, ...
2
votes
1answer
92 views

SIP Provider stores credentials, is it required for some SIP phones?

My SIP provider stores my SIP call time password as AES encrypted in stead of hashed. I understand that SIP authentication has the capability to NOT store the password, and in stead store a ...
0
votes
1answer
162 views

Storing encrypted data for offline use

A user downloads a file from a server. I want to store that file locally on the user's machine so they can view offline. For protection, it should be encrypted while not being viewed. My theory is ...
13
votes
1answer
2k views

PayPal encrypted with obsolete cryptography

My Chrome just complained from PayPal's security, similarly to this issue: Google Chrome "Your connection to website is encrypted with obsolete cryptography" The identity is verified, but ...
15
votes
2answers
2k views

Does AES-192 provide better encryption than AES-256?

this wikipedia article describing AES says: Related-key attacks can break AES-192 and AES-256 with complexities 2^176 and 2^99.5, respectively. Does this mean that AES-256 is actually a weaker ...
1
vote
0answers
38 views

What is the difference between XOR and poly-XOR? [on hold]

What is the difference between XOR and poly-XOR in encryption?
2
votes
3answers
94 views

How do I deal with browsers complaining that my MediaWiki website has unsecure resources? [on hold]

I recently bought a subscription to a NameCheap shared hosting plan, and I plan to primarily run MediaWiki on it. I've managed to setup everything fine except for the SSL encryption. When I visit my ...
1
vote
2answers
124 views

Securing user's data against an attacker that may gain server root

I'm designing a web application that is going to handle very sensitive data, storing it on behalf of its users. A kind of online safe, if you will. A user's secure data should only be visible to her, ...
1
vote
1answer
955 views

Using AES as a Stream Cipher

I need to send a lot of small messages that are usually between 128 bits and 256 bits long, and each message is encrypted with a separate 128 bit AES key. Therefore, to send each message with the key ...
-3
votes
0answers
37 views

Best Cipher for Client Application to Web Server [on hold]

I am making a Application that requires a login. I'm using a HTTP Server for accounts. My question is, what is the best Encryption/Hashing/Cipher to use in this case ? I know that SSL/TLS won't cut ...
12
votes
8answers
47k views

How can I determine the encryption strength of an SSL connection

If I've connected to a https url, how can I determine the cipher strength of the connection? My understanding is that after the asymmetric public-key handshake the information is encrypted using a ...
4
votes
2answers
534 views

Are temporary files an issue when opening and editing an encrypted 7z file?

I am new to security and encryption. I want to store important information like passwords and pin codes so I don't forget them. So far I have been using LastPass but I would prefer a solution I ...
-1
votes
1answer
48 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 ...
3
votes
1answer
67 views

toy OpenPGP encryption with manually generated keys

I've been playing around with OpenPGP encryption for a little while. Here are the steps I've followed: Generate an unencrypted public/private key pair in my keyring with gpg --gen-key. Dump the ...
2
votes
1answer
202 views

Is this a sensible way to encrypt user data?

I want to make a site for storing sensitive user data, that retains per-user data encryption in the event that the database is compromised. This is the model I was thinking of, to give the best ...
3
votes
2answers
73 views

Can the intended recipient be derived from a public-key encrypted ciphertext?

Assuming you have a list of possible recipients' public keys, and a ciphertext encrypted with one of those public keys, would it be possible to determine which public key?
1
vote
1answer
7k views

Encrypting string in JavaScript and decryption in Java [on hold]

I would like to know if there is any library to do encryption in JavaScript and decryption in Java. I have already tried many APIs, but am not getting the same values in Java. I want public-private ...
-2
votes
1answer
66 views

What is encryption by RSA with AES? [duplicate]

By visiting some websites, like bank websites, we can see for example: TLS_DHE_RSA_WITH_AES_128_CBS_SHA, 128 bits, TLS 1.0 I would like to know: What does mean CBC? TLS 1.0 is an old version, is ...
2
votes
0answers
89 views

Was TRESOR integrated in the Linux kernel?

If a computer is switched off, the data can stay in RAM memory for a while; decaying over about 5 minutes. This can be made longer by cooling the chips: ...
107
votes
2answers
68k views

What is the difference between https://google.com and https://encrypted.google.com?

Is it there any difference between the encrypted Google search (at https://encrypted.google.com) and the ordinary HTTPS Google search (at https://google.com)? In terms of security what were the ...
1
vote
1answer
209 views

Chat encryption system avoiding protocol sniffing and then key+decryption replay?

I'm working on a chat system and I want to add it some kind of security (not just HTTPS with SSL since I've read it can be sniffed and decrypted with a few tools). Now, my knowledge in cryptography is ...
1
vote
1answer
37 views

Secure socket communication between iOS device and 3rd party server

I'd like your advice on what is the best approach for the challenge in my hands... I'm developing an extension to a 3rd party software. I'm doing my development using Python/Twisted/Autobahn. The end ...
0
votes
0answers
38 views

Designing a security system for road pricing

It's my first semester with Information Security and I still feel a little lost. Sorry in advance for stupid mistakes I may have made. the examples in round brackets below are my own ideas, wrote ...
6
votes
1answer
508 views

can multiple encryption of data with multiple keys increase the security?

I mean: does encrypting data multiple times have an effect on diffusion and confusion? Does it increase security, or does it have no effect? Is it useless? Does it make it harder to break the secret, ...
0
votes
1answer
99 views

What are the best practices to store payment processor dev/API keys?

I am integrating with multiple payment processors which have their set of public/private keys. This would be used in conjuction with per user keys, to bill clients. I was wondering what is the best ...
1
vote
0answers
14 views

using crt for encrypting files/texts [duplicate]

I work with GPGTools under Mac where, after creating a public/private key pair for myself, I usually get .asc from other users, import it and then I'm good to go. Now, I got an actual certificate from ...
48
votes
3answers
55k views

Is Telegram secure?

There is a new WhatsApp-killer application called Telegram. They said that it's open source and that it has a more secure encryption. But they store all the messages in their servers and WhatsApp ...
1
vote
0answers
33 views

What web browsers support ECC vs DSA vs RSA for SSL/TLS?

We are updating our wildcard certificate and see that we have the option to use both RSA or DSA with Symantec (for free), while Digicert offers 3 options for wildcards ECC, DSA and RSA. Is there a ...
0
votes
1answer
76 views

Decrypting SHA-256 with known plain text

If i have a SHA-256 hash and I know what could be the crypted string is it possible to decode it faster? Lets say I know the string is formed like this : %d-%d-%d-%s %d being numbers from 1-25 %s ...
1
vote
1answer
154 views

What are the risks of encrypting a database with a single symmetric key

An application is required to store sensitive data* on each user. Additional columns are added to the database which store cyphertext encrypted on the application server. The algorithm of choice is ...
2
votes
3answers
135 views

Completely encrypting virtual machine (for free) [closed]

I know in VMware workstation there's the option to encrypt a virtual machine. Is there a free way to do this without VMware workstation? I'm aiming for the fullest encryption and encapsulation ...
0
votes
1answer
21 views

SQL Server Asymmetric Encryption Keys

I have used SQL Server database with data to be encrypted and I will use symmetric key for encryption and will encrypt it by asymmetric key now comes the question how to give user permission to ...
0
votes
0answers
13 views

SQL Server Format-Preserving encryption

I have old system with database that has table with column of type char(20) and the customer decided to encrypt that column for some business needs however for some system integration needs the ...
0
votes
0answers
17 views

ISAKMP Allows Weak IPSEC [closed]

I have a Sonicwall NSA 4500 firewall and on a PCI scan done a report came back saying "ISAKMP Allows Weak IPSEC Encryption Settings". Best I can find is this might be a false positive related to ...
3
votes
3answers
51 views

encryption vs access control comparison

I have a very basic and simple question about two security concepts. Both encryption and access control are used for privacy and to prevent unauthorized users from accessing some object (eg. files, ...
14
votes
2answers
11k views

Decrypting TLS in Wireshark when using DHE_RSA ciphersuites

How can I decrypt TLS messages when an ephemeral Diffie-Hellman ciphersuite is used? I am able to expose the premaster secret and master secret from the SSL Client. Using that, how to decrypt the ...
7
votes
2answers
126 views

Can symmetric key cryptography provide identification?

I understand that PKI uses digital certificates to link a public key to an entity, but is there anything similar for symmetric cryptography. If, theoretically, PKI didn't exist, how do you know you ...
2
votes
1answer
328 views

Requiring 2 keys to access a content

I need to use an external service that can only be accessed by password. I don't like the idea of storing the plaintext password on the server, but AFAIK there's not much I can do. Considering this ...
4
votes
3answers
42 views

GnuPG symmetric encryption yields different output

I have a use case where I want to commit symmetrically encrypted source code using GnuPG (think of Coursera assignments for backup and collaboration). I encrypt/decrypt all sources in a batch with a ...
5
votes
3answers
416 views

Any reason not to encrypt a 32 byte value by XORing it with a PBKDF2 hash?

Ordinarily I'd use PBKDF2 to generate a key which i'd use with AES. But seeing as the hash is going to be as long as the data I need to encrypt is there any disadvantage to just XOR'ing it? My ...
2
votes
1answer
71 views

Is the same decryption key used for data on the server as locally with Lastpass?

Lastpass stores the password databases encrypted on the server. Does it give a database to anyone who asks? If no, then what authentication (i.e. password) is used? I use Lastpass on multiple devices ...
4
votes
1answer
128 views

Should veil framework produce packed and obfuscated binaries which bypass virustotal?

I have been working with the veil framework to test an internal IDS system I have in place. I have used a public malware sample which produces an 8/53 hit score on Virustotal and run it through the ...
0
votes
1answer
55 views

Moving /tmp to an encrypted tmpfs

BLUF: I'm using an SSD on my system, so my primary reason to use tmpfs to increase the life of my drive by moving high read/write files to volatile memory. But from a security point of view, I'd also ...
0
votes
1answer
121 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 ...