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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What flexibility does a “Third party gamma” offer to U-Prove deployment?

The U-Prove SDK has the following comment: (link) // 1: CA-RA split (a party trusted by the issuer provides the gamma value) Given that the Gamma value (if provided) overrides the Attributes value, ...
33
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1answer
8k views

Why does AES encryption take more time than decryption?

While I was studying the time consumed by some methods I found that encryption take more time than decryption. Is this right? I am using AES (the same steps will be taken during the enc and dec)
5
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2answers
1k views

Is XML encryption actually broken?

I recently stumbled on this post: XML Encryption Broken, Need To Fix W3C Standard I was expecting to find lots of information online about it, but there isn't actually all that much detail. Since I'm ...
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5answers
2k views

Encrypt-function inside PHP code that you have to publish

If you write a PHP application, where you have to deliver the compiled code to the customer, how could you include a functionality to send encrypted data from that application to others, and include ...
4
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3answers
7k views

How secure is ionCube compiled code?

I use ionCube to keep the code I write concealed for my customers. If I would store a password inside the code and compile (not encrypt) it with ionCube encoder, would it be possible for a potential ...
1
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0answers
95 views

Is this any recognizable encoding or cipher? [closed]

I've been watching the Marble Hornets videos on YouTube (basically, an independent film series about a group of kids chased by the "Slender Man"), and in this video I saw something interesting. ...
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2answers
301 views

IPTable Security between two servers

Is using IPTables to only allow traffic between two servers considered an acceptable practice? For example TCP traffic on a defined port. I realize this is referred to as an ACL but how secure is ...
3
votes
2answers
856 views

How safe is a PGP private key that has “escaped”, but without its password?

Assuming your PGP private key is protected with a password, and it "escapes", but the password does not, how worried should you be? Obviously in the real world, you would immediately revoke the key ...
0
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1answer
83 views

Performance issues while applying encryption at host or guest level?

One of the security expert here suggested me to apply encryption at guest(virtual machine) level rather than applying at host level with good reason. Before applying that I want to know what can be ...
0
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1answer
199 views

Which one is best, host or guest encryption?

Can anyone please tell me which option is better, I mean whether I should encrypt my data at virtual machine level or guest level in cloud? I tried to investigate it but did not find best solution so ...
3
votes
2answers
751 views

Store private key on server, then use k1 to log in, k2 to verify HMAC and k3 to decrypt private key

I'm working on a proof-of-concept program to encrypt email with less difficulty for end-users with a process like: To create an account: Generate a random salt and IV, and get a password from the ...
17
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1answer
3k views

Why can't I use the same key for encryption and MAC?

I wrote a simple file encryption program as an example of how to do encryption correctly, but after reading a questions about encryption + MAC, I think I made a mistake by using the same key for both. ...
3
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2answers
115 views

How to ensure two messages are from the same party

I need to verify that two messages, that came over distinct channels, come from the same origin: without knowing anything about the origin beforehand the channels are one-way, only one message may ...
22
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2answers
6k views

How does non-ephemeral Diffie-Hellman key exchange become compromised in SSL when the RSA private key is leaked?

From my understanding, one of the major reasons we recommend Diffie-Hellman Ephemeral (e.g. DHE or ECDHE) over non-ephemeral DH, for SSL / TLS, is that compromise of the RSA private key (i.e. private ...
4
votes
1answer
3k views

Credit card data security - hashing, truncation and encryption

A question with a similar title has been asked before, but it doesn't answer my specific question here. PCI DSS permits storage of truncated and encrypted data, or hashed and encrypted data. It ...
2
votes
1answer
635 views

How to manage passwords in a multi-tenant surrounding?

I am building a multi-tenant application in a shared database model. I would like to encrypt sensitive data so that only a particular tenant could have access to his data. What is the best mode to ...
1
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1answer
2k views

Man-in-the-middle attack over an encrypted channel

I learned recently about man-in-the-middle attacks and came up with this question. Let's say we have two computers who try to communicate over the network. Each computer has an encryptor and a ...
24
votes
9answers
9k views

Is encryption in HTTPS done by the browser or by the system?

This may be a common sense question, but I am not able to find any documentation on this after searching on google for a long time When browser makes a HTTPs request, does it encrypt the data then ...
7
votes
1answer
2k views

Working out how to decrypt encrypted string when knowing the plain text

I have access to a system which I have been asked to create a data export routine for. However, the address details are encrypted and the original sourcecode/password are lost. However, I am able to ...
8
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1answer
2k views

Build a secure channel without SSL/TLS

I'm looking at possible options to build a secure channel between multiple embedded devices with limited cryptography capabilities and an HTTP server (It could be some sort of web service). 1. ...
7
votes
3answers
936 views

How to fuzz proprietary protocol over SSL?

I'm doing vulnerability research on a client/server architecture that uses a custom proprietary protocol sent over SSL (port 443). I need to be able to intercept the traffic, and be able to view it in ...
7
votes
3answers
3k 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 ...
13
votes
4answers
6k views

Why does PGP use symmetric encryption and RSA?

Looking into the details of Pretty Good Privacy, I'm confused as to the reasoning behind encrypting the message with a session key and the key with the recipient's public key via RSA. I fail to see ...
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2answers
2k views

Can the U.S. goverment crack encryption? [closed]

Does USA government have the sufficient processing power to crack keys in matter of seconds? Let say 2048-bit RSA, for example. Since the RSA algorithm was developed by USA government (NSA?), I ...
2
votes
1answer
2k views

Are very short messages secure using Public Key Encryption? [duplicate]

Say Alice publishes her public key and then disappears from public view. Bob then needs to send a message to her that's either "OK" or ":(" so he takes her public key, encrypts his message and then ...
5
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4answers
597 views

A Secure Email Host Architecture

How would one go about creating a secure email architecture? I'm thinking specifically about protecting email from routine surveillance from oppressive regimes and corporations. I had a think about ...
13
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3answers
606 views

Can I use the same password both for SRP and for client-side encryption?

Suppose a less-than-trusted server is used to store users' confidential data (encrypted at the client side), and both tasks - authentication and encryption/decryption - should be doable with a single ...
2
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1answer
744 views

Protect an application that uses internet from packet sniffing

I developed a stand alone application such a way that, application use a remote service (using SOAP/REST) which available WWW. I am using HTTPS though out the application calls. It was perfectly ...
3
votes
1answer
121 views

Online only encryption

I understand that one can use for example PGP (or GnuPG) to encrypt emails and files. (And I understand that there are other programs out there that will do "similar things") This, though, requires ...
38
votes
5answers
3k views

Client-side encryption, but cloud service can still decrypt data in the event of a death? Is this possible?

I've been worried about this password manager, PasswordBox that seems to be gathering quite a bit of steam lately. They seem to have raised VC funding and are offering a free password management and ...
-1
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2answers
797 views

How to minimize your fingerprint, or become invisible on the web? [duplicate]

With all of these news stories about the government reading emails and snooping information from other sources, what are ways to minimize or eliminate an organization's ability to actually track and ...
-1
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2answers
207 views

Security and privacy in email and other communications [closed]

In the light of newly discovered events like the NSA's PRISM program, I'm really concerned about the privacy & security of my personal emails. Chances are governments already have backdoor access ...
11
votes
4answers
4k views

How likely/possible is it that the NSA have broken common encryption techniques such as SSL/TLS?

Jumping on the NSA/Prism questions bandwagon - There's been a lot more attention drawn to facilities such as Room 641A which indicate that the NSA has been, amongst other things, applying mass ...
2
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2answers
2k views

Login system using authenticated encryption without storing user password

I'm not a security expert, so I might be asking a silly question, but let me describe what I am thinking about. First, I know that a lot of web sites store hashed/encrypted passwords which could be ...
8
votes
2answers
486 views

Encrypting an empty database field versus leaving it empty

In a system where personal information stored in a database is encrypted, but one of the fields only contains data in a minority of cases, would it make more sense to leave the field empty, rather ...
27
votes
8answers
3k views

Share certain information only after death

After your death, you want to make sure that a special someone gets a vital piece of information (like the password to your bank account), but: You don't want anyone else to be able to get that ...
1
vote
1answer
1k views

What is the difference between an HTTPS traffic setup with Stunnel and a SSL-VPN

We have a scenario where we cannot connect to our stunnel server running on port 443 on our network, which only allows access to Internet via a proxy server. On the contrary, when we tried a SSL VPN ...
-4
votes
2answers
252 views

Problem with Encryption Protocol

I have a question about a encryption protocol, if it is good or not. Bob and Alice communicate over an insecure channel( a possible attacker can listen). An expert suggests the following protocol to ...
-1
votes
1answer
849 views

Properties for cryptographic hash functions (preimage, second preimage and collision resistant)

While studying computer security at university I have been asked this question: There are three desirable properties for cryptographic hash functions: Preimage resistant, Second preimage resistant, ...
2
votes
2answers
218 views

What are the vulnerabilities of reusing passwords for generation of keys and encrypted files?

The main reason why reusing a password for different accounts is not recommended is that if the password is compromised, all accounts are compromised. This question is about vulnerabilities other ...
9
votes
2answers
2k views

Do keyfiles actually add any meaningful security in the presence of strong passwords?

In the context of protecting access to local encrypted files or devices against a determined (and competent) adversary, is there any reason to believe that the use of a key file actually presents a ...
28
votes
3answers
6k views

Why can a Tor exit node decrypt data, but not the entry node?

Me -> Node A -> Node B -> Node C -> destination The documentation on Tor always states that only the exit node C can see plain text data. How is this possible without me talking to Node C ...
0
votes
0answers
38 views

How can I determine the encryption used by knowing input and result? [duplicate]

Is it possible to determine the encryption or hash used if I know the original input and final output? There is a similar post here: Determine encoding/hashing methods used based on knowing the input ...
-6
votes
2answers
525 views

the Informix password crack

I get some hash like: username sowainformix salt 7307821250330563328 hashed_password HaHvvzanjp_lPZgHLu0KHquN.Q4t98EF48csXk1QTJs hash_type SHA-256 updated flags ...
-1
votes
1answer
1k views

Is AES more secure than Rijndael? [closed]

Which algorithm is generally considered to be more secure, and is AES-192/AES-256 still considered to be secure? After reading this it's lead me to belive that the Rijndael algorithm would be a more ...
2
votes
1answer
816 views

AES in CTR mode with same random IV to create same ciphertext

I am currently working on a little project. I am trying to generate an AES key with that I would like to encrypt a private RSA key. I have to do it this way. However, I do not want to save the AES ...
11
votes
3answers
1k views

Reason for writing Self-Decrypting Virus

What is the rationale behind writing a self-decrypting virus? By this I mean a virus that has it's payload encrypted, decrypts at runtime and runs it. How does this protect the virus from antivirus ...
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votes
2answers
9k views

Is it possible to encrypt a virtual machine using virtualbox? [closed]

Is it possible to encrypt a virtual machine using virtualbox, and not leave accessible to the users of the machine where it hosted, and not allow any file to be extracted it with some program ? The ...
7
votes
2answers
16k views

Decrypt from cipher text encrypted using RSA

I am sniffing a client side application traffic and I found some encrypted data. I am not able to decrypt it. Information which I have is Public Key: ...
7
votes
2answers
363 views

Why standards organizations give so short protection times for 128 bit encryption?

According to this and this, seems even 128 bit encryption should remain secure for a much longer time than what security organizations say. I saw the standards with this: http://www.keylength.com/en/...