Tagged Questions

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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0
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1answer
353 views

How are TLSv1.0 ciphers negotiated as TLSv1.2?

I'm a little confused about something I am reading in Bulletproof SSL. "TLS 1.2 is the only protocol that allows suites to define their PRFs. This means that for the suites defined before TLS 1.2 ...
1
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2answers
92 views

Are digital signature algorithms subject to the same types of attack as public-key encryption algorithms?

I understand that digital signatures are usually implemented by encrypting a message digest with a private key, decrypting the resulting signature with a public key, and verifying that the message ...
1
vote
2answers
110 views

ECDSA ciphers and forward secrecy question about key exchange

I have heard that with forward secrecy that the ECDSA ciphers generate different keys for "each session" because they are not dependent on the private key of the server. My question is how is "each ...
48
votes
6answers
15k views

Can my IT department read my Google Hangouts chats while at work?

Is Google hangouts encrypted? Would my work's IT guys be able see pictures and text I send while on a work computer? Yes I know I shouldn't be sending stuff I don't want them to see while at work, but ...
2
votes
1answer
47 views

Possibility of using CA as an attack point by governmental organizations under their pressure

I was always concerned about the model of trust behind CA stuff we use . Well, for most of us, it is OK to trust them, since they are reliable organizations with a bunch of solid experience. ...
1
vote
1answer
238 views

Security margin of a winzip, Winrar password of 64 characters against GPU cracking

what s the longterm security margin of of a winzip or Winrar file encrypted with aes-256 and a password consisting of 64 completely random characters set a-z 0-9 and other printable special ...
2
votes
1answer
159 views

Is encrypting something more than once safer than hashing more than once?

I am aware of the implications that hashing something more than once correctly will increase the security of a system, but doing it incorrectly will decrease it, as noted here and on various other ...
-2
votes
2answers
59 views

Identifying/decrypting hashed/encrypted data [closed]

This weekend I took part in an security challenge. I had great fun doing it but i found a huge gap in my knowledge that I'm really keen to fill and hope someone here can help get me pointing in the ...
4
votes
2answers
1k views

Extract AES key by comparing plaintext and encrypted data

Is there a kind of analysis which would enable me to get AES key which was used for encrypting arbitrary data while I have both original and encrypted version of data ? The problem is that the AES ...
2
votes
1answer
97 views

Drawbacks to only using TLS 1.2 ciphers in OpenSSL

I understand you would not want to do this as it would limit compatibility for older devices and platforms. However if someone were in an all TLS1.2 environment, say a very well managed internal ...
0
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3answers
91 views

Why do we use such a redundant language (English) for network communication? [closed]

I have heard throughout the internet that English is incredibly redundant. So why do we turn English messages in to a cipher which is then, from my understanding more vulnerable to letter frequency ...
-1
votes
1answer
26 views

Choosing right way to secure access to server access via socket

I have an application running on a server, that has an exposed socket to the Internet to communicate with client that is/are application(s) on a phone. How would one go about properly securing the ...
1
vote
3answers
109 views

How are HSMs used in payment processing on the server?

I came to know recently that HSMs are used in credit card processing on the server side but since I don't work in that space and stumped as to why its needed. I can see it used in an ATM machine - ...
4
votes
1answer
98 views

Is there a secure way to create and distribute Shamir Secrets?

This Shamir Secret sharing utility consumes the secret key, and then generates N keys that must be manually distributed to each person. This is probably fine for most low-security situations, but not ...
2
votes
2answers
307 views

Easiest solution for automatic encryption of files on Dropbox?

I don't trust Dropbox to keep my files secure. In fact, the same goes for all the other file clouds. What I'd like is a easy and cross platform means of encrypting files that I add and read from ...
0
votes
2answers
168 views

Using different algorithms to slow down GPU password cracking [duplicate]

I have some job related files I have already compressed with 7Z. I have protected each with good 10 character passwords consisting of upper, and lower cases, numbers and special characters. And I ...
1
vote
1answer
279 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 ...
1
vote
1answer
55 views

Entering payment information in Android Apps

I'm concerned how android apps that integrate payment processing deal with secure financial information.When purchasing through these apps the apps show the Webpage of the bank asking for credentials. ...
2
votes
1answer
96 views

Are all TCP connection protected by IPsec?

I hope this question fits this stackexchange: From what I understand, IPSec takes care of encrypting everything above the IP layer (transport, application). Does that mean that if I open a socket ...
2
votes
0answers
169 views

Some http requests are not send encrypted by vpn! Why?

I subscribed to a VPN service recently, and installed wireshark to take a look at the traffic sent from my computer. Practically all of it goes through UDP protocol, encrypted. But there are two HTTP ...
0
votes
0answers
50 views

Payment Application Integration - Encryption or HMAC

Doing an integration with an online payment provider. Payment provider will be making a web request to my server to provide some information about the basket content. On my end there's no payment ...
2
votes
2answers
56 views

How to identify Encryption algorithm for data coming in field/attribute values of an xml

I have data coming in the form of XML with certain XML attributes being encrypted. I am very new to encryption/decryption. So I would like a detailed explanation on how to find the encryption ...
4
votes
2answers
117 views

How does an insecure RNG affect cryptography, and how do I measure the corresponding loss of security?

Suppose a given random number generator has poor entropy, and is compressible by any compression algorithm (zlib, bzip2, lzma, etc). Specifically the issues with this RNG are: Bad entropy Bad seed ...
-1
votes
3answers
105 views

What's the most secure way to send information from one device to another?

I need to send sensitive information from one piece of hardware to another. I was thinking wifi, but if someone obtains the password, it wouldn't be encrypted. I don't think you can use ssl unless ...
5
votes
1answer
244 views

How is ZixCorp able to provide email encryption without a password?

I am trying to understand how/if an email I received is being encrypted. A financial institution sent me a verifiable email (i.e. not phising) asking me to fill out a pdf form to complete a ...
2
votes
3answers
152 views

Adding photos to Truecrypted, airgapped laptop from camera safely

I have a Truecrypted, airgapped (no internet connectivity at all) laptop that I use as a completely secure computer for sensitive files. I want to add images from my iPhone (I know), camera or other ...
0
votes
2answers
97 views

How to combine a key and a password in practice

Alice wants to encrypt her data. She is not comfortable with using only a password. While she prefers to use a properly random crypto key, she isn't confident she can protect the key file from theft ...
0
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0answers
84 views

What else do I need to secure my data in an encrypted non-system drive?

I have to use an almost seven years old laptop running Windows 7 ultimate and want to encrypt my hard disk to protect my private data (e.g. documents, pictures, Dropbox, etc.). I encrypted a ...
0
votes
0answers
40 views

Composing and Inverting Symmetric Encryption Keys

First Question: Using a symmetric encryption algorithm E on a message M, users usually send E(M) to the recipient and then the recipient will compute E^-1(E(M))=M to retrieve the message. If M is ...
1
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2answers
70 views

Is there a secret-sharing public-key-encryption-based service? [closed]

I need to share some sensitive information with someone else who can only communicate via E-mail. I don't love the idea of sharing this information freely over email in plain text, so I was ...
1
vote
2answers
141 views

Will an IP packet to the own IP address ever leave the computer? [duplicate]

I am working on a system that consists of several applicaitons communicating with each other. Some of these applications will run on the same server and some will run on a different one. So there is ...
2
votes
3answers
97 views

How can DH provide a known secret to two parties over an unencrypted connection without it being intercepted via MITM?

Without using Private and Public keypairs, i do not understand how Diffie-Hellman is able to generate a secret key between two parties on the internet without passing something between that could be ...
1
vote
2answers
154 views

Can ISP use MITM attack to “break” encrypted traffic?

Use connection of A and B as an example. Their communications were encrypted by Public Key Encryption. Before they exchange their public key, ISP MITM attacked. A got "B"'s public key (ISP generated) ...
0
votes
2answers
68 views

Is server-side access control sufficient or should I encrypt querystrings

I've got an ASP Classic system that passes around sequential ids corresponding to keys in the database. I had gotten an encryption module (chilkat, an activex control) that I was using to encrypt and ...
5
votes
1answer
110 views

Is a Linux environment PCI compliant if the swap file is not encrypted and PANs are loaded into RAM?

Is a Linux environment PCI compliant if the swap partition/file is not encrypted and PANs are loaded into RAM by an application?
0
votes
1answer
71 views

A folder lock/encryption program that can do this? [closed]

I am looking for a program that can lock or encrypt folder, but in case if my laptop is stolen and C drive is reformatted and reinstalled, and i have locked folders on D drive, these folders to remain ...
0
votes
1answer
123 views

XTS vs AES-CBC with ESSIV for file-based filesystem encryption

In a blog post I recently read called "You Don't Want XTS," the author explains some of the pitfalls of using XTS to encrypt filesystems. Specifically, he recommends against ever sharing encrypted ...
25
votes
2answers
3k views

Break the popularity contest crypto

There is a very interesting puzzle on the Programming Puzzles and Code Golf site to Rearrange pixels in an image so it can't be recognized and then get it back. I understand that this is not ...
0
votes
3answers
897 views

VPS Privacy: OpenVZ vs KVM vs Xen

Considering OpenVZ, KVM and Xen: Which VM technology is the most difficult for the host's administrators to access given an encrypted root partition? Can I have a reasonable expectation that rogue ...
0
votes
2answers
165 views

Hacking machines using internet packets [closed]

I have a friend (X) who hacked the whatsapp account of someone (Y) using iphone. He told me that he sent a packet to the iphone of Y that appears as a normal whatsapp message but now he can see all ...
-1
votes
1answer
143 views

PCI compliant transparent data encryption at disk/folder level on Windows?

Is there a way to achieve PCI compliant data encryption at disk/folder level in Windows in a way that is transparent to applications(they must be able to write/read to encrypted folders/disks as if ...
0
votes
2answers
78 views

Encryption mechanism

I want to send data over the Internet securely. For that, I am using an public key of the receiver to encrypt the data. In this case, if an intruder in the network modifies the data, like placing the ...
1
vote
2answers
106 views

Database compromised and some passwords cracked

I run an MMORPG game and today while moving from one server to another, apache failed and listed some of the data on the server including a back-up of all the source code + database which a few people ...
1
vote
1answer
42 views

Importance of password strength with secure element?

Greetings SE security community. Background: I have a number of items like certificates, databases, and encrypted file systems that require private keys. In order to avoid having duplicates of these ...
0
votes
1answer
405 views

How is the Premaster secret used in TLS generated?

I believe that it uses some combination of the random values sent in the hello messages. From RFC 2246: (TLSv1.0) RSA encrypted premaster secret message Meaning of this message: If RSA is ...
1
vote
2answers
59 views

pci compliance and temporary files

Does storing temporarily a non-encrypted file containing some PANs violate pci requirements? (for example because it is being processed by an application, or to open it on a file editor)
-1
votes
1answer
323 views

PHP/Ajax Data transmission security

I'm learning about web security mechanisms. I have developed the following system in PHP and JavaScript: assuming that I have a page named: messages.php which is a real-time chat system. first when ...
0
votes
2answers
74 views

How to generate a superkey to decrypt strings

I'm working on an application where users have a key or password generated by me that is used to encrypt a string. Each user has their personal key, and no user should be able to decrypt another ...
0
votes
1answer
36 views

Can any ECC field element be safely serialized as “compressed” and then restored as uncompressed?

I have a library that stores all its ECC Field Elements in uncompressed form, in a bloated Base64 XML format, and storage has become a concern. (We want to support QR code as a form factor,etc) ...
4
votes
2answers
269 views

Safety of using web based proxy?

Lets say for example I have to use a public online proxy like https://www.zend2.com to load a PHP webpage controlled by me containing sensitive data over HTTPS. How would I make sure that the proxy ...