Tagged Questions
-6
votes
1answer
49 views
How to determine decrypt type? [closed]
That my excryptyion: $apr1$Xd.M80Hx$CMwMdjv79eiE4PfFjuI8R.
How should I determine the current encryption?
Thanks you people.
-2
votes
0answers
48 views
Unable to understand Word 2007 document encryption [closed]
So I read the documentation here:
It seems there are 3 principal modes of encryption. I created a mock document and made it password protected. After some snooping, I guess my document uses the RC4 ...
-1
votes
1answer
48 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, ...
0
votes
0answers
29 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 ...
-4
votes
1answer
93 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
3answers
133 views
Salting in encryption (rather than hashing)
I am aware of the benefits of adding a salt to values that are hashed using a one-way function. Is adding a salt to a value that is being encrypted (using symmetric encryption) considered to be good ...
11
votes
1answer
226 views
“Please Enter Nth Character” without HSM
This question has been asked a few times, but always in the format
"How does examplewebsite.com implement their 'please enter xth yth and zth characters of your password' function?"
And the ...
6
votes
1answer
105 views
Encrypting short identifiers?
I am developing a webapp that does not reveal record count, because it hides the primary key. I am looking for a better way to do this.
My favorite idea is to encrypt the ID itself with a block ...
3
votes
2answers
249 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 ...
3
votes
2answers
268 views
File security when encrypting files directly with the openssl command / and what about SHA1 hashing password first?
I've been using this command to encrypt files for a while now:
openssl aes-256-cbc -a -salt -in secrets.txt -out secrets.txt.enc
Then I type in a password.
Can someone tell me, roughly speaking, ...
0
votes
1answer
138 views
Determine hashing algorthim only with known input and output
Given the input:
test
A system generates the following output hash:
0x001F41B6A0534D3B851D69EFE6237F550100000010D5F4FC65E64BCFDBF2590212E4411C44942C6C734C00ACFE13B958DCAB3614
I do not know ...
1
vote
5answers
307 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 ...
1
vote
3answers
173 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 ...
3
votes
3answers
288 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)?
4
votes
2answers
1k views
openssl: recover key and IV by passphrase
A large amount of files were encrypted by
openssl enc -aes-256-cbc -pass pass:MYPASSWORD
Openssl should derive key+IV from passphrase. I'd like to know key+IV equivalent of that MYPASSWORD. Is ...
5
votes
3answers
772 views
Choosing a session ID algorithm for a client-server relationship
I am developing an application which has a client-server relationship, and I am having trouble deciding on the algorithm by which the session identifier is determined. My goal is to restrict ...
2
votes
6answers
277 views
Does shuffling a hashed password increase its security?
I am making a web app and I'm now stuck on making the login secure. I'm thinking of adding a salt to a user-inputted password and then hash it. (md5 or sha for example)
and then I will reshuffle the ...
2
votes
3answers
189 views
Password Security: Encrypting salt [duplicate]
Possible Duplicate:
Password Hashing add salt + pepper or is salt enough?
I'm new to security and trying to understand why encrypting or hiding a salt is not considered useful. I've read ...
2
votes
3answers
371 views
rsa encrypted hash == rsa signature
$ echo -n "1327943823" > test_ok.txt
$ openssl dgst -sha1 -binary -out test_ok.sha1 test_ok.txt
$ echo "GURbsl4CFPCG83RCZxsEpoRleXicXQhH1OC4Fk77b7EMj2g8aHUhD/L+sm
...
2
votes
1answer
105 views
Seeding GPG keygen with a hashed secret [duplicate]
Possible Duplicate:
Tool for public key cryptography where password is the private key?
I was wondering if you guys could clue me in to potential problems with using a hashed password as ...
2
votes
1answer
109 views
Security of re-encryption with a list of pre-computed password based keys
I have a problem where an encrypted file stored on a server needs to be decrypted through a precomputed list of passwords that are used one time only - OTP applied to encryption basically. The file is ...
16
votes
1answer
340 views
Doing a dictionary attack on RSA if you have the public key?
I'm trying to learn exactly how RSA works. Currently I have a very, very simplictic overview that goes like this.
Having the public key allows you to encrypt things. Encrypting the same message ...
3
votes
3answers
164 views
How to know if its the same User?
I asked a question awhile ago asking how to make an efficient encrypted chatroom. What I ended up doing was Making each user generate a 4096 bit RSA KeyPair, share their public Keys, and then one of ...
4
votes
2answers
276 views
What is the purpose of using Youtube-style alphanumeric ids as URL slugs?
I asked a question on StackOverflow on how to generate the alphanumeric/base64 resource IDs that Youtube, Instragram, and others use to identify videos/pictures/etc. Discussion led to the question of ...
3
votes
1answer
148 views
DPAPI offline attack by cracking windows password?
I'm thinking of using DPAPI to protect configuration file information in my program. After doing some reading on it, it looks like it uses the user's Windows password as part of the encryption ...
1
vote
5answers
572 views
making an iPhone/Android app which sends a user password to my server, how to secure?
I'm making an iPhone/Android app for my website, users already have an account on the website and the app will allow them to login.
I don't have SSL on my website, but it's just a reviews website and ...
6
votes
3answers
314 views
How secure is HTTPS with weak ciphersuites?
Today I came across the website https://mtgox.com/, which claimed to be secure because of the Verisign certificate. I checked the certificate out of curiosity (it's the first thing they claim, let's ...
2
votes
7answers
493 views
Tracking unique web site visits without logging IP addresses
On Monday, some IP address xxx.xxx.xxx.xxx visits my site. I log it.
On Tuesday, another IP address yyy.yyy.yyy.yyy visits my site. I log it.
If the two IP addresses are equal, I throw out the ...
41
votes
5answers
5k views
Is sending password to user email secure?
How secure is sending passwords through email to a user, since email isn't secured by HTTPS.
What is the best way to secure it? Should i use encryption?
4
votes
5answers
280 views
Can hash functions be used with CTR or OFB mode?
I have been writing a class that encrypts and decrypts with block ciphers. I want to use Counter Mode(CTR/CM). We know that Counter Mode generates a keystream basing on counters, then XOR the ...
-2
votes
1answer
208 views
What encryption hash function I should use for password securing? [duplicate]
Possible Duplicate:
How to securely hash passwords?
What is the best encryption algorithm? MD5, SHA1, SHA2 or maybe something else? Can you explain me why?
2
votes
3answers
875 views
When to use the different types of Encryption / hash algorithm?
I'm studying for CISSP and know they will ask what type of encryption to use in different situations. Does such a list exist or is there a general rule of thumb to use?
1
vote
4answers
279 views
Are there vunerabilities with this authentication mechanism?
I am trying to come up with a way to implement token-based authentication for a REST API without the need for SSL. The goal here is to avoid sending any sensitive information across the wire.
I was ...
1
vote
2answers
237 views
Hash, encryption of file… key? Need help [closed]
So my previous question was with some help on pcap files as I am doing a security course and we have a challenge to figure out what was going on in our network. Now one of the files I retrieved is an ...
1
vote
0answers
256 views
what is this hash type? [closed]
Actually I have this hash but I don't know what cryptographic hash function generated it.
4753305A7A673D7A5A442156 I know password is 12345678 I extracted this pass from PLC device
Mitsubishi
4
votes
3answers
2k views
What's the advantage of using PBKDF2 vs SHA256 to generate an AES encryption key from a passphrase?
I'm looking at two comprable pieces of software which need to encrypt data on disk using a passphrase. One uses PBKDF2 to generate the encryption key from a passphrase, while the other uses two rounds ...
-6
votes
2answers
798 views
Is AES slower to encrypt than MD5?
Is this the right interperation of this diagram:
http://www.cryptopp.com/benchmarks.html
AES/CCM
MiB/Second:61
Cycles Per Byte:28.6
MD5
MiB/Second:255
Cycles Per Byte:6.8
And does that ...
4
votes
4answers
619 views
Is encrypting a salt value with a password/plaintext a viable alternative to straight up hashing?
The basic problem, as far as I can tell, is that hashing's flaw is that the password is in the hash. Asymmetric encryption's flaw is that the password is encrypted and can be reversed.
The posts ...
3
votes
2answers
719 views
What is better salted hash or openssl encryption?
Im using php and I was looking to store passwords in a mysql database. I was wondering what would be safer to use a salted hash or openssl encryption? If i use a unique random generated salted hash ...
-1
votes
1answer
159 views
How to find the encryption of a cipher and apply it to another key [closed]
I am very new to cryptography so please help me out with this one
I have a Question Key-1 which + some encryption gives Answer key-1. I have to find the encryption to apply it to another Question ...
3
votes
2answers
393 views
Security of GPG encryption with AES and MD5 if MD5 is broken
I have a file encrypted with gpg, using AES256 and MD5. Suppose that the MD5 hash function is broken, but not the AES cipher. Does that make it easy to crack decrypt the file?
10
votes
4answers
604 views
Encrypting IP addresses in a MySQL database
I'd like to encrypt IP addresses in my MySQL database, with the following constraints:
Does not need to be resistant to attackers that can execute queries.
Must be resistant to attackers that have ...
1
vote
1answer
189 views
How to check for a key *and* store encrypted data?
I wish to create a system wherein I store encrypted data.
Users can access this data if they have the key. If they give a wrong key, they don't get access at all. If they give the right key, they get ...
5
votes
2answers
549 views
Authenticated Encryption vs. contained and encrypted checksum/hash?
So I read through http://en.wikipedia.org/wiki/Authenticated_encryption and http://www.cryptopp.com/wiki/Authenticated_Encryption and I don't seem to be following the concept.
From the simple ...
3
votes
11answers
3k views
Definitely safest password storage scheme?
I already asked this on StackOverflow but I was suggested this would be a better suited place and I found no way to "move" the question so I have to copy it.
Believe, I know, there are hundreds ...
61
votes
11answers
9k views
Why are hash functions one way? If I know the algorithm, why can't I calculate the input from it?
Why can't a password hash be reverse engineered?
I've looked into this ages ago and have read lots on it, but I can't find the explanation of why it can't be done. An example will make it easier to ...
3
votes
1answer
468 views
Bcrypt as a key derivation function?
I read a lot of entries at stack exchange about bcrypt and why it is supposed to be better than PBKDF2 in terms of password storage.
I'm asking now if bcrypt is better than PBKDF2 in terms of key ...
4
votes
2answers
859 views
openssl_digest vs hash vs hash_hmac? Difference between SALT & HMAC?
openssl_digest vs hash vs hash_hmac
I want to use SHA512 for storing password.
Which of the above methods are best to use? Why?
What is the difference between SALT & HMAC?
I just read ...
9
votes
4answers
2k views
Does symmetric encryption provide data integrity?
Let's say I have one server that encrypts a file with a symmetric key, e.g. AES-CBC, and sends it to clients that decrypt it. Does that provide data integrity when decrypted? Or is it possible for ...
4
votes
5answers
2k views
SHA, RSA and the relation between them
SHA is the hashing mechanism. However, RSA is the encryption algorithm.
So does RSA algorithm use SHA hashing mechanism to generate hashing keys which in turn is used to encrypt the message??
...
