Tagged Questions
3
votes
1answer
116 views
Known plaintext; What cipher is being used here? [closed]
plaintext: CANDY VERY CRANBERRY
ciphertext: TXOtWjYhVk 8&O$4AmSA
plaintext: http
ciphertext: cZf.
plaintext: http
ciphertext: r5Hz
This is definitely somehow decodable from ...
0
votes
0answers
19 views
Why this k parameter is in unary in adversary PPT algorithm? [migrated]
While reading some text on cryptography, I found that algorithm A, that the adversary (called Eve by convention) runs to break the cipher message, needs two parameters, candidate message (y) and ...
20
votes
2answers
1k views
Does versioning an encrypted file make it less secure?
Suppose I use KeePassX as a password manager, and I store the kdb file in Sparkleshare folder as a way for backing up and syncing with multiple devices.
The kdb file in itself would be encrypted, but ...
15
votes
2answers
321 views
Homomorphic encryption used for e-voting?
I was reading wikipedia about homomorphic encryptions, and one part got me a bit confused:
"The homomorphic property of various cryptosystems can be used to
create secure voting systems, ..."
...
2
votes
1answer
66 views
How to Verify the Identity of the Caller of a Web Service
I have a server which is composed of a page and a web service. The web service is intended to be used by a Windows Phone mobile application that I will develop myself.
Now, my question is, how do I ...
3
votes
1answer
82 views
Windows Phone and Hardcoding Values
Let us say that I have a Windows Phone application. If I hardcode a private key in the Windows Phone application, can people extract it once the application is released to the public on the Windows ...
1
vote
1answer
70 views
SSL Communication and Proxy
Let us say that I have a client and a server communicating using SSL.
If a hacker sets up a proxy between the client and the server, will he be able to decrypt the data which is being sent?
-1
votes
1answer
172 views
What is a man in the middle attack?
My university provided me with the following slide which is confusing me:
From my understanding, what is happening here is that Trudy (Person in the middle) is pretending to be Alice. Bob then ...
1
vote
1answer
64 views
Symmetric Key Cryptography vs Public Key Cryptography [duplicate]
I understand what the two are so need to go into detail about that, however what I'm curious about is in what kind of situations would we use one over the other? It feels to me as if Public Key ...
0
votes
1answer
64 views
Determine the Identity of Caller
Let me explain my situation.
I have a provider which is made up of a registration page and a web service. Online vendors (clients) register with the provider by providing details such as username, ...
-7
votes
1answer
62 views
Asymmetric encryption algorithms [closed]
What are the best asymmetric encryption algorithms out there? I am trying to use RSA in my project howoever I have read that it is not quite secure as other asymmetric encryption algorithms.
3
votes
1answer
51 views
Clarification on Digital Certificates
I used the makecert tool to create:
self-signed certificate
client certificate
These are the commands I used:
makecert -n "CN=MatthewCA" -r -sv MatthewCA.pvk MatthewCA.cer **for self signed ...
2
votes
1answer
40 views
Sending Digital Certificates
I used the makecert tool in order to create:
a self-signed certificate
a server certificate using the self-signed certificate
a client certificate using the self-signed certificate
I then ...
2
votes
1answer
62 views
Security Certificates - Tools to Generate Security Certificates
I want to create a self-signed certificate that will be installed as a trusted certificate authority.
I then want to create another two certificates which are signed using the private key of the ...
1
vote
1answer
92 views
The request was aborted: Could not create SSL/TLS secure channel Exception
Let me explain my situation.
I created a self-signed certificate and installed it in the Trusted Root Certification Authorities section in MMC.
I then created two certificates using the self-signed ...
3
votes
4answers
234 views
Is it possible to configure any of wifi protocols so that the network is undetectable?
I am wondering if it possible to configure my DD-WRT router so that the wifi network I am using is undetectable - impossible to tell if there is any network broadcasting even if there are clients ...
4
votes
1answer
88 views
Switching to new encryption method (without losing data?)
Let's say you have a website that provides a service of some kind. Users can log in, they can store some kind of data, and there's various types of encryption in place to keep it all safe. Passwords ...
4
votes
3answers
99 views
What SSL options should not be used?
What SSL options should be avoided, due to recently discovered weaknesses? This might include symmetric algorithms, or MAC functions.
4
votes
4answers
163 views
Why do you need message authentication in addition to encryption?
I've been reading up on Authenticated Encryption with Associated Data. The linked RFC states:
Authenticated encryption is a form of encryption that, in
addition to providing confidentiality ...
1
vote
2answers
216 views
Questions to hybrid encryption. RSA with AES
I want to use a hybrid encryption in my application, so after reading a lot of lines I ended with this implemantation, please critizie it ;) (I want to stick to .Net)
byte[] aesKey = ...
1
vote
1answer
103 views
Symmetric or asymmetric encryption for JSON Web Token?
We're planning on using JSON Web Tokens (JWT) for our authentication server, and I am currently evaluating which encryption approach to take for the JWE token.
There appear to be two options for ...
1
vote
1answer
130 views
Exchange of DEK and KEK (encryption keys) between app server and key server
In my application, it is required to encrypt a user's data before inserting it into the mysql database. I am using AES algorithm to encrypt the data using a 256 bit hash (and is calling it Data ...
3
votes
2answers
245 views
Does it make any difference of the order Hashing and Encrypting in terms of security?
I am implementing a password vault program with java. I have programmed a triple DES for encryption and a SHA256 for hashing.
My question is would it make any difference if I first hash the raw data ...
1
vote
3answers
111 views
Cryptography key gathering tool
I am wondering if there exist a tools which can return the value of the one of the private key if the following are known:
1) Encryption Algorithm
2) Public key
3) Plain text
4) Cipher text
Or may be ...
3
votes
1answer
125 views
Why do PGP master keys only have a single subkey, and tie certification with signing by default?
After learning more about PGP subkeys and how to split apart the roles of (S)igning, (E)ncryption, (A)uthentication and (C)ertification, I discovered that in most cases(?) a default master key has a ...
2
votes
2answers
108 views
Many-time pad on image data, how to proceed?
I have raw image data that is XOR-encrypted with a fixed-size one-time pad repeated over the length of the image. I know what the format of the image data container is so I can successfully retrieve ...
5
votes
1answer
93 views
Security and authentication problem
We have a sample scenario and we would like to receive some feedback and some solutions regarding possible security schemes.
First of all, lets imagine a real world scenario:
Imagine that a user ...
3
votes
1answer
291 views
Will double encryption increase the security of cipher vs bruteforce?
Lets say, I have a function
encrypt(mes,key)
where :
mes = message
key = key
Length of key is 64bits.
Lets say, that only way to crack my cipher is brute force attack.
If I use
...
4
votes
3answers
176 views
Can encryption twice with two keys in different sequences lead to the same result?
I am looking for an encryption algorithm for one of my current papers. The basic requirement is that, suppose I have two keys k1 and k2, and the E(k1,t) means encrypt t with key k1.
Are there any ...
1
vote
5answers
2k views
Cracking CISCO ASA Passwords
I've got a copy of a Cisco ASA config and i want to crack the following example passwords
I've got the following lines in the config
ASA Version 8.4(2)
!
hostname ciscoasa
enable ...
3
votes
2answers
171 views
Is it reasonable to prevent timing attacks by using fixed processing time
I have systems that perform cryptographic operations within a SSL/TLS tunnel. My concern is that I may leak timing information when encrypting, decrypting, or hashing.
Part 1
Is it a good idea to ...
3
votes
2answers
87 views
Securing Time Sensitive Data
I have a number of time sensitive, embargoed pieces of information that I need to distribute over the Internet and have received at a precise time. I'm currently dealing with the problem by uploading ...
3
votes
4answers
264 views
Can an attacker reuse stolen SSL private key to recreate that domain on his server
Say my domain (https://example.com) SSL private key has been stolen and was not protected by a passphrase then.
Can the attacker uses that key and certificate to host the same
domain on different ...
3
votes
2answers
145 views
What are the differences between ssh generated keys(ssh-keygen) and OpenSSL keys (PEM)and what is more secure for ssh remote login?
I have learned there are 2 methods to make SSH remote login easier and secure , those are;
ssh generated keys (using ssh-keygen)OpenSSH Keys
PEM (.pem) keys usually generated with OpenSSL (Amazon ...
1
vote
5answers
286 views
Is SHA-1 encryption?
I have read that SHA-1 is a cryptographic hash function. On an exam, SHA-1 was given as a possible one-way encryption algorithm. Does SHA-1 require a key as input? Is a key required to qualify as ...
0
votes
1answer
104 views
Tracking information on HTTPS connection
My organization uses cyberoam firewall. They are monitoring all activities including my search text in Google, Wikipedia etc. So recently i changed to HTTPS versions and now using HTTPS connections of ...
0
votes
1answer
118 views
Is TLS secure when full eavesdropping on the network occurs? [duplicate]
Possible Duplicate:
How is it possible that people observing an HTTPS connection being established wouldn’t know how to decrypt it?
Alice connects to Bob's site via a TLS secured connection ...
3
votes
3answers
271 views
Hash Function Xor
For a hash function what is the best secure method, XOR or Concatenate:
h(data1 XOR data2 XOR data3 XOR data4) ? or use h(data1||data2||data3||data4)?
2
votes
1answer
77 views
Kerberos realm understanding
Could someone summarise why realms are necessary in Kerberos and the advantages of the concept.
I'm struggling to isolate everything I know / beginning to understand into some well defined points for ...
3
votes
2answers
304 views
how strong is AES without salt
The AES cryto library provided to us from company, does not generate a different encrypted value for plain text.
If text is "abcd" , it will generate the same encrypted value over multiple ...
0
votes
1answer
133 views
Storing Private Keys Generated on Server with specific User's Password Securely
I am currently building a system (PHP Web Application Framework) that creates an RSA Key Pair for a user to allow other users to send secure information from one to another. The public key is ...
4
votes
2answers
1k 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 ...
0
votes
1answer
153 views
How does the YubiKey Validation Server work from an encryption perspective?
Many YubiKey servers rely on the free cloud hosted authentication that comes with the product, but I'm interested in keeping all cryptographic material in my control. For that reason I am looking at ...
4
votes
1answer
154 views
Combining MAC and Encryption
What is the most preferred and secure way of combining both Encryption and MAC. There was a lecture on different combining strategies adopted by different protocols on a cryptography course by ...
0
votes
0answers
81 views
What McEliece key size can provide standard security today? [closed]
i don't wanna use RSA because it will be plaintext very soon but we can't stop using internet to send private data.
Does McEliece cryptosystem provide security today ?
What McEliece key size is ...
1
vote
2answers
457 views
KDC(Key Distribution Center) vs Asymmetric Key Exchange
Today I was reading notes about cryptography and I came across a problem that exists in Symmetric Key encryption, which is how to share the secret key across the network.
1st Method :
Make use of ...
2
votes
2answers
273 views
What hardware technology (GPU, FPGA) is fastest at generating RSA keys?
I'm interested in generating RSA keys in rapid succession and am looking for the correct hardware to so. I think what I'm looking for is very similar to a brute force attack on RSA keys, but my ...
8
votes
3answers
141 views
Is it preferable to perform encryption using database functions or code?
Several databases I am familiar with provide functions or modules for encryption. Examples include dbms_crypto for oracle databases and built-in functions for MySQL.
Most of the commonly used ...
4
votes
3answers
219 views
Two step encryption
Consider the following user case:
I have some sensitive data (eg: credit card number)
I encrypt this data and store it in the database
Now I want to send this data to a user X, but I don't want to:
...
2
votes
1answer
108 views
Design of Initialisation Vector
I understand that an IV (initialisation vector) should be both unique and unpredictable, but I have found little guidance as to which is most important.
For an AES cipher I have a block size of 128 ...
