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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2answers
45 views

Prevent MITM between custom phone app and local server

We're building a Wifi enabled device. The device will be installed locally on each client's office and people in the the small office will connect to this Wifi enabled device, They will send/receive ...
5
votes
1answer
69 views

Showing bank routing/account numbers, and storing them safely

EDIT: This is for the UK/Europe region. I've been scratching my head reading other posts similar to this one about safely storing bank routing and account numbers. I know that routing numbers can be ...
4
votes
2answers
139 views

Why does the first call to DecryptUpdate in AES-CBC return 16 fewer bytes?

While decrypting a file by CBC mode of AES algorithm, the output length is 16 bytes lesser than that of the input length. For example if you pass a buffer of 512 bytes it decrypts 496 bytes. It ...
1
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1answer
61 views

Storing encryption key in a cookie?

I have a website issue that I am addressing by storing an encryption key in a cookie. I want to describe my issue and my solution, and see if someone smarter about such things than I thinks this is a ...
1
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1answer
48 views

Android email encryption [on hold]

Is there a reliable (in terms of security), open-source application for handling (send/receive + en-/decrypt) encrypted emails on Android? Something like TextSecure for emails. I just found a command ...
0
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0answers
42 views

How to secure peer-to-peer chat (includes video) - school project [on hold]

The main idea is that there are two types of communications, text via TCP and video via UDP. Application should be peer-2-peer working in private network where everyone has their own IP address, ...
0
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3answers
98 views

Please critique my encryption scheme for a very small microcontroller [on hold]

I am new here and not an cryptography expert; but I have been using encryption library for a while. My company is working on a small hardware device. It is powered by a microcontroller so memory is an ...
17
votes
3answers
2k views

Why do HTTPS requests include the host name in clear text?

I'm having a little bit of trouble understanding why the HTTPS protocol includes the host name in plain text. I have read that the host name and IP addresses of an HTTPS packet are not encrypted. Why ...
0
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1answer
50 views

How to pick an encryption algorithm (cipher) and mode for PHP's mcrypt, for encrypting passwords?

There are numerous algorithms listed in the PHP documentation: http://php.net/manual/en/mcrypt.ciphers.php How strong is each one and what criteria to use when picking one? Also the ...
1
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1answer
128 views

Possible shellcode mailed to me

When I opened my email this morning I found a rather odd message in my mail box. It didn't seem like your every day spam email as it looked like a base64 encoded string and nothing else. Here is a ...
0
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1answer
57 views

Hidden OS: Decoy OS ≠ Hidden OS?

I wanted to use two different OS then two OS equal in the distinct functions: Hidden OS: Linux Decoy OS: Windows Has how? because what I have read until today were processes done with even OS, I do ...
39
votes
8answers
6k views

Why can't you work backwards with public key to decrypt a message?

As the title suggests, I am curious to know why you can't work backwards using a message, public key and encrypted message to work out how to decrypt the message! I don't understand how a message can ...
0
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1answer
34 views

What are the risks of file server access over wireless? [closed]

In our office, all computers connect to the network over wireless. The wireless is protected by a pass phrase and communication is AES encrypted. On the same network is a file server that is used ...
4
votes
1answer
28 views

Secure encrypted storage of values that allows DB lookups?

I'm developing a system that has to store Finnish national identification numbers as securely as possible while allowing "does this identification number exist in the system?"-type queries over a web ...
0
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0answers
36 views

Encryption and decryption of plain text using stream cipher algorithm [on hold]

As we know that in stream cipher data are encrypted bit by bit as in block cipher block by block. So in stream cipher key will generate as depend on plain text. So I have doubt that if in any stream ...
20
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5answers
3k views

Is it possible to “read” secure (using SSL or TLS) messages if you know the message?

If I am communicating over a secure line (secured using SSL or TLS) and I send the server a message. Could someone eavesdropping tell what that message was if they knew before hand a list of messages ...
-1
votes
1answer
44 views

What would be a problem with using a block cipher to encrypt the traffic of an online game?

I have a question and can't really find the answer. Here are my 3 possibilities. I think it is the 2nd one but want a different opinion. a)The communications require a key exchange not supported by ...
2
votes
1answer
70 views

How does this encrypted webmails works?

In the last days I was looking on Tutanota, ProtonMail, LavaBoom, and others webmails that promise to respect users privacy. For all those, the one I most liked was Tutanota. I did few tests with ...
3
votes
1answer
91 views

Secure Connection between two mobile (Android and/or iOS) devices

I've a Device A which will communicate with multiple devices on a network (BLE and/or NFC). All the devices will be handled a Token upon authentication which somehow needs to be transferred over to ...
-1
votes
3answers
155 views

If TLS 1.2 is considered unbreakable, why do the NSA and other agencies invest in supercomputers? [closed]

If a 2048-bit RSA key and a 256-bit AES key are considered to be unbreakable within the foreseeable future by any kind of computer, why do the NSA and other intelligence agencies invest in ...
1
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1answer
56 views

How to send secure messages from a microcontroller circuit?

I have an Arduino with a GSM shield. This enables me to send short arbitrary messages to any server. What do I need to do to enable sending "secure" messages (that cannot be intercepted and have a ...
0
votes
2answers
127 views

Is all encryption compromised? [closed]

Assuming that what I read about the Nazi enigma encryption being broken in ww1 and ww2, where the code breakers hid the fact that they had broken the code, allowing the world to feel that the code was ...
1
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1answer
31 views

Is it possible to convert a gpg key to a different encryption algorithm [duplicate]

Maybe the answer to this question is a simple and unequivocal "No", followed by "How can you possibly think that this is possible?". And if I think about it rationally this seems to be the only ...
3
votes
0answers
97 views

Is it possible to break enigma code with a todays laptop [migrated]

I have a 500 characters enigma encoded text. Random rollers were used (not the ones from wikipedia). I know of this flaw. I can guess some words that sould be in the text, but this probably doesn't ...
5
votes
2answers
264 views

Linux kernel entropy - does it matter to /dev/urandom and what is a minimum?

This question had been asked several times, but still something's not clearly understood from other answers I have a few servers running with a custom built linux kernel (minimal driver modules etc), ...
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0answers
56 views

Copyright Issue? [closed]

Few months ago, I have created a few icons for my app and after copyrighting them, I published them on my website. I clearly stated on my website that it is illegal to use my icons for commercial or ...
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votes
0answers
24 views

Where can I get Comparative Surveys with Statistics of Usage of the existing Biometric Template Protection Techniques? [closed]

I am looking for survey papers or research papers with comparative statistics of usage of the currently existing biometric template protection techniques among biometric systems developers / biometric ...
2
votes
1answer
42 views

What is the default cipher algorithm for GnuPG?

I know, that one can force GnuPG to use AES256 for encryption with gpg --cipher-algo AES256 or with a special setting in ~/.gnu/gpg.conf. But, what is the default cypher algorithm for GnuPG, if I ...
2
votes
1answer
79 views

Plain text password emailed back during registration [duplicate]

I would like to ask if the passwords in the database are not encrypted if during registration I am receiving plain text password with username.
2
votes
0answers
58 views

How do I allow for anonymous encryption? [closed]

I have a protocol I am designing that requires anonymity and privacy. My idea is to have a minimum number of hops in the network before the message can be sent to its intended destination. The ...
2
votes
1answer
23 views

How is ECIES available in FIPS Validated libraries?

ECIES is Elliptic Curve Integrated Encryption Scheme. Both Certicom's SecurityBuilder and RSA Data Security BSAFE provide ECIES. Both are FIPS 140 validated, and both clearly list ECIES in their data ...
3
votes
0answers
56 views

How does Silverlight protect the AES keys it gets from PlayReady? [closed]

I'm doing some research about how Silverlight protects AES keys. Here is the scenario: There is a smooth stream live encrypted channel service. When i log in to the service and tune the channel, ...
1
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0answers
31 views

Total, initial, hard drive encryption speed with VeraCrypt [migrated]

Context: I decided to encrypt a 2TB Internal Sata II hard drive I use for personal files (photo collections, tax prep PDFs, hosting a synced Dropbox folder, some non-HD video files, driver install ...
2
votes
1answer
160 views

linux hidden OS

I have been reading about hidden volume OS with truecrypt, and now with its successor, VeraCrypt. https://veracrypt.codeplex.com/wikipage?title=VeraCrypt%20Hidden%20Operating%20System But Couldn't ...
1
vote
3answers
145 views

Is this approach to backups secure?

I've got an existing (personal) backup service which I'm rewriting from the ground up to be secure. At present, I just store files (and diffs) in AWS S3 with no encryption. It works fine but I'd like ...
0
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0answers
23 views

How does the Blowfish algorithm key initialization work [migrated]

I'm having some trouble understanding the Blowfish encryption algorithm. From the Wikipedia article... "The secret key is then, byte by byte, cycling the key if necessary, XORed with all the ...
4
votes
3answers
217 views

Is AES 256 secure enough for putting Backups to AWS or Dropbox?

How long would it take with current hardware to hack an Disk Image which was encrypted with AES 256? I ask because i want to backup personal files (contracts, tax-things, code, keys, private ...
1
vote
1answer
37 views

Reading encrypted data before sent to remote server

I'm developing a mobile app (Android only for now) to provide a disposable e-mail service to users. Users will be given temporary e-mail addresses so they can receive and read e-mails for a certain ...
1
vote
1answer
23 views

What is the “segment size” when using Cipher FeedBack (CFB) chaining mode?

When using CFB chaining mode with AES, I see instructions that the "plaintext length (in bytes) must be a multiple of segment_size/8" (also mentioned here). What does that mean?
2
votes
1answer
22 views

Does any DNS Recursive resolver accept a “DNSSEC-only” option under DNSCurve?

I want to use DNSCurve (for privacy) to a trusted DNSSec resolver (for integrity), and want to ensure that I can tell a recursive resolver (like 8.8.8.8, or OpenDNS) that I only want DNSSec queries. ...
1
vote
0answers
47 views

Logging in from one CMS to another

Two websites with different CMS, user should type login & password on one website and needs to be logged in second website automatically. Now i have this method, it works but i want to know - is ...
0
votes
2answers
78 views

What options exist for authenticated full-disk encryption?

Title says it all really. I'm toying with the idea of storing some disk images in "the cloud", but am concerned about the possibility of an attacker manipulating cipertext to do evil things once it's ...
0
votes
1answer
50 views

Using randomly generated numbers to authenticate with a Relay server

I'm developing a public VoIP relay server, that will help bypass internet firewalls by allowing two clients to connect with it and then it will relay data between the two. Both clients will connect ...
1
vote
0answers
35 views

get a key HEX from wpa/wpa2 handshake [closed]

Can I get a key HEX from wpa/wpa2 handshake, or from the network in another way without knowing the passphrase? Example: Network SSID: linksys54gh WPA passphrase: radiustest Hexadecimal key: ...
3
votes
2answers
1k views

Chrome showing cryptography as 'obsolete'

Similar to this question, Chrome is showing the connection cryptography as obsolete. Opera, IE and Firefox seem perfectly fine with the connection. My guess would be the message authentication is ...
0
votes
1answer
42 views

Which parameters can I use to analyse my cipher? [closed]

I have made a new methodology for a symmetric key cryptography in which I have used matrix operations, a boolean function and ASCII conversion. Please suggest me the possible parameters to judge my ...
2
votes
1answer
98 views

Strategy for encryption before cloud storage

Apologies if this has been asked before. I am looking to encrypt documents before storing in the cloud. There will be a separate metadata storage, which could be either internal or cloud hosted. My ...
-1
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0answers
23 views

How does the certificate authority generate a signature F? [migrated]

E=encrypt(K,M) - is message M encrypted with key K gives encrypted text E M=decrypt(K,E) - is encrypted text E decrypted with key K gives message M KCA−pub,KCA−priv - is the private-public key pair ...
0
votes
2answers
56 views

Determine Security Of A PDF File [closed]

How do I find the exact encryption on a PDF file? I can't seem to get a direct answer on the net. For example how do I tell if a document is PDF 1.1 - 1.3 (Acrobat 2 - 4), PDF 1.4 - 1.6 (Acrobat 5 - ...
3
votes
2answers
131 views

Is there any reason for using private key 2 times when creating security hash?

One of the payment solutions for the websites provides the following way of creating security hash for payment link: hash = sha1(private_key + payment_params_json + private_key); Is there any ...