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

1
vote
1answer
72 views

How to generate Initalization Vectors correctly

I'm working on a project that splits large files into several encrypted fixed-size blocks (e.g. 4KiB). Those blocks shall be used to be stored persistently on a storage device. Blocks are encrypted ...
2
votes
3answers
149 views

Should we encrypt in-app user messaging?

We have an app running where among other things people can send messages to each other. Obviously admins and content managers that have access to CMS can see what people are sending to each other. Is ...
-3
votes
1answer
53 views

Algorithms to store and send data

I would like to store data, and send it by mail. What is the best way to encrypt it, and being able to decrypt it? My guess would be RSA, but is there a better way? (Considering that the other person ...
0
votes
2answers
194 views

Security of several files all using same password/key (7zip, AES256)

I'm working on a simple secure mirror for potentially untrusted services like Dropbox, Owncloud and so on. (Current code may be seen here: http://www.codeduce.com/extra/secure_mercurial) Currently ...
1
vote
0answers
36 views

Needed: Reference data on the rate of adoption of secure email protocols [closed]

I am working on a security presentation in which I need to show that the incidence of unencrypted email protocols (e.g. POP, IMAP without STARTTLS) over the past 10 years has decreased and the amount ...
0
votes
1answer
54 views

Using multiple hash-functions along the line [duplicate]

I was wondering what the effect on strength/security is If I would use an aggregate of multiple hash-functions. For instance, I don't want to sent passwords in plain text (although it's over an ...
4
votes
3answers
974 views

RSA key length vs. Shor's algorithm

I have just read a passage in Zeilinger's book about quantum world. My question is: Suppose there exist quantum computers. Given that a quantum computer can use Shor's algorithm, what key length ...
5
votes
3answers
4k views

How easily could be truecrypt and EFS cracked in this scenario

I suspect some info was subtracted in the past months from my laptop. Therefore Im looking for methods to encrypt my data. I want to try using truecrypt for the sensitive files folder plus EFS for ...
1
vote
2answers
284 views

Is SSH secure and what are the recommended modes of operation?

Given the recent confirmation of weakened and broken encryption schemes and implementations, how does the community feel about the security of SSH? It seems there has been very little discussion ...
42
votes
3answers
2k views

What kinds of encryption are _not_ breakable via Quantum Computers?

There's the recent article NSA seeks to build quantum computer that could crack most types of encryption. Now I'm not surprised by the NSA trying anything1, but what slightly baffles me is the word ...
4
votes
3answers
174 views

Is there any reason in particular encryption keys aren't arbitrarily large?

It's my understanding that the more bits an encryption key has, the longer it takes to break the encryption. What is the down side of having a larger encryption key or why don't we see keys of size ...
3
votes
2answers
236 views

Why would you need a salt for AES-CBS when IV is already randomly generated and stored with the encrypted data?

I was looking at this code and came across these comments which says encrypting without a salt is insecure. Why would it be insecure when you are already using a random IV for each value? I think the ...
0
votes
4answers
214 views

Is knowing 'a' encrypted with 'b' and 'b' encrypted with 'a' a possible threat?

Excuse me for question name, but I couldn't find any other suitable title. I want to validate client connecting to the server. My algorithm looks like that: Clients sends his login - plaintext ...
1
vote
2answers
166 views

How secure are the GPG/PGP keyservers?

Importing a GPG key with a KeyID or fingerprint seems to rely on keyservers. Doesn't this invite man-in-the-middle attacks, in which someone would alter the keys to allow them to decrypt the data? ...
1
vote
1answer
191 views

What does Gazzang zNcrypt actually protect against?

In an effort to increase security of our website, I'm reading up on Gazzang zNcrypt, which claims to protect data in databases from breaches. Technically, it seems to do filesystem encryption. As far ...
3
votes
3answers
211 views

validate file encryption without decryption key

I may be asking for something impossible here. I want to know if it is possible to set up a 3rd party storage system where the service provider cannot decrypt the clients files, but can de-dupe the ...
21
votes
5answers
13k views

What ciphers should I use in my web server after I configure my SSL certificate?

There are many great questions that ask what is the best certificate to use for a website; but once the certificate is purchased, there is also the possibility to choose or edit the Cipher list. ...
-3
votes
2answers
96 views

Facing hard encryption [closed]

I have a little problem with encryption. I have this cipher text "AA969CF9657F77C597C8EAFF1594D59374E4977F" and i know that correspond to "http://jogos.meo.pt/". I have another samples, but i can´t ...
2
votes
5answers
251 views

Is asymmetric encryption vulnerable to man-in-the-middle attacks?

I'm looking for ways to send private messages over a public channel, and in doing this I stumbled in asymmetric encryption, which is just perfect for what I was looking for at first - A and B ...
0
votes
1answer
106 views

How can brute force scripts tell once they're found the correct key?

If you have a random block of data and you encrypt it with a key, how can a brute force script tell when it has found the correct key? Is it possible without some sort of reference to the original ...
0
votes
1answer
91 views

Any issues with this security design for cloud storage? Server doesn't even need to know password to log someone in

I've created an algorithm I think I'm going to use for a cloud storage service I'm developing- if there are no issues or vulnerabilities with it. It's this along with TLS and forward secrecy ...
-1
votes
4answers
205 views

Is it possible to digitally sign information with a password?

I'm creating a cloud storage service and need to have the ability to provide reliable security for clients. In my previous question, I used a different schematic and said I would post a new question. ...
1
vote
1answer
44 views

How to change TEA round count? [closed]

I cribbed the public domain TEA source from wikipedia ( http://en.wikipedia.org/wiki/Tiny_Encryption_Algorithm ), looks like this - uint32_t v0=v[0], v1=v[1], sum=0, i; /* set up */ ...
0
votes
3answers
90 views

Best way to store passwords for a LAN tool?

I am making an app in Python for linux as a front end to the router (to automate some tasks). But I need to log in to the router before I can do any operations on it and since it uses a http-auth I ...
6
votes
2answers
373 views

ECC based Client Certificate import in Chrome/Mozilla in windows

I have deployed a PKI server and successfully able to generate the ECC based user or client certificates. but non of the web browser support ECC as public key. I have tried different tools and also ...
4
votes
3answers
2k views

Nested Truecrypt containers

Which is more secure: use one container encrypted with AES > Twofish > Serpent = 768bits key size make an AES container, and inside it make another Twofish container then inside it make a third ...
2
votes
2answers
256 views

Risks of client-side encryption using Stanford Crypto Library

I'm building a simple web application for encrypted chat. Each message will undergo 256-bit AES encryption on the client side, using the Stanford Javascript Crypto Library. No unencrypted data or ...
9
votes
2answers
500 views

Can I use hardware random number generation on my computer? Am I already using it?

A lot of computer security depends on encryption: SSL connections, TCP packet sequencing, encrypted files, etc. These depend on random number generation to ensure that attackers can't guess the ...
1
vote
3answers
145 views

S/MIME doesn't protect against a stolen password, right?

We're setting up S/MIME so that we can send encrypted emails. However, I have a bit of a stupid (and maybe obvious) question... If someone steals a password for either the sender or the receiver, ...
2
votes
2answers
309 views

What are the vulnerabilities of using a 256 bit encrypted PDF file over email?

I often send confidential documents to others using encrypted PDF files (i.e. files with a user password, and typically with an owner password as well) to prevent both accidental forwards and ...
0
votes
2answers
349 views

Look over my Web API Authentication Scheme

I want some advice on my Authorization/Authentication scheme that I will be using for my Web API that I am writing. Firstly the Authentication : 1) When a user first logs in and they are authorized, ...
13
votes
2answers
727 views

Does the haystack theory work

The haystack theory is the recommendation to put repeated characters in your password in order to make it harder for brute force to reveal. Does this have any mathematical basis? Or is it snake oil?
0
votes
2answers
91 views

Basic simple encryption with already installed tools

If you are exchanged email messages with people using Linux, Windows and some odd Mac and want to implement some really basic security, encrypting all messages, just trying to avoid some ...
0
votes
1answer
73 views

vsftp encryption algorithm

I want to configure VSFTP for ftps protocol and it has some choices to select the encryption type: tlsv1, sslv2, sslv3. I read that tls version 1 has some security issues but in the man page it says ...
1
vote
1answer
1k views

4096 Bit RSA Encryption Cracked [duplicate]

I'm new to encryption and still learning about it; I overheard someone this weekend mentioning that 4096 bit encryption was "cracked" by listening to the CPU and searched for this to confirm it ...
3
votes
1answer
153 views

Securing wifi with encryption

So I have been hearing that using WPS Pin is not secure at all and that there are available downloads that can brute force attack the pin until it uncovers it depending on what encryption you use. I ...
4
votes
4answers
358 views

Is it a good idea to have a “master” password?

Though I do have a good memory of passwords, it is quite impossible to have one password per application. Yet, it should be... My current way to deal with passwords is to have five passwords and to ...
0
votes
1answer
197 views

How secure is a partial 64bit hash of a SHA1 160bit hash?

So http://en.wikipedia.org/wiki/SHA-1 SHA-1 produces a 160-bit (20-byte) hash value and As of 2012, the most efficient attack against SHA-1 is considered to be the one by Marc Stevens with ...
2
votes
2answers
209 views

Consider a “zero-knowledge” file host such as mega.co.nz. How can one prevent users to upload unencrypted content?

I am wondering how could a zero-knowledge host such as mega.co.nz prevent users to just upload files in clear, and, for example, to discredit the site by uploading a large quantity of illegal material ...
2
votes
4answers
316 views

For someone who has a key and ciphertext, is it possible to find out what encryption algorithm was used?

I am new in cryptography, and while learning a different questions pop up in my mind. Here is one of them. For someone who has a key and ciphertext, is it possible to find out what encryption ...
-2
votes
1answer
77 views

What is this encrypted with or where can I find examples of encryptions to compare it with? [closed]

I have a hash thingy I am trying to decode and I have done relatively little with encryption, though I would like to try to learn some more. The hash is: 1YMTpavsFq7ykllC3CCsg3e1li31re1nROxuW1wqIqpk ...
5
votes
1answer
2k views

ECDHE_RSA and gmail

I'm using Chrome on Ubuntu Linux to connect to Gmail. The connection info says that ECDHE_RSA is used for the https symmetric key exchange. Based on my understanding of TLS and Gmail, my client ...
0
votes
1answer
114 views

Encrypting content using same secret key as hash?

OK - I'm trying to design a system that can provide personalised/differentiated content at minimal expense to the server. One of the designs I'm currently exploring is where the request is somehow ...
6
votes
2answers
2k views

WPA2 Enterprise AES encryption key size?

I have recently set up a RADIUS server with EAP for my wireless router, however, I have some questions about the key size and how WPA2 enterprise (AES) works in general. I have read that in ...
3
votes
2answers
289 views

Why don’t SMTP servers just require all senders to be authenticated before accepting mail?

Why don’t SMTP servers just require all senders to be authenticated before accepting mail?
2
votes
3answers
188 views

Can a zero knowledge proof of voting be made using a trusted auth server (without client side crypto)?

Questions: Can one implement a secure voting system having all the features described below? e.g. without disclosing any individual's vote to the government server (or the third party), preserving ...
0
votes
2answers
57 views

Challenges in authentications

I have a case where I have a set of low compute capable processors connected to a gateway processor. I need a way of authenticating these processors to gateway processor. The main things are: I need ...
45
votes
8answers
4k views

Online backup : how could encryption and de-duplication be compatible?

A "soon to enter beta" online backup service, Bitcasa, claims to have both de-duplication (you don't backup something already in the cloud) and client side encryption. ...
1
vote
2answers
106 views

Securely passing critical data to other domain

My company owns a domain A.com , and subsdiary is on B.com B.com redirects their users to A.com for accounts registrations. Post successfull registration , A.com logins that user ( User doesnt get to ...
1
vote
3answers
247 views

Does HTTPS encryption work when there is invalid or there is no certificate?

When I have a website run on https and there is no certificate, there is wrong certificate or out of date like here does encryption still work or not?