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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OMAC: multiplication in a finite field - how can I compute the correct polynomial

From The EAX Mode of Operation: We explain the notation used in the definition of OMAC. The value of iL (line 40: i an integer in {2, 4} and L ∈ {0, 1}n) is the n-bit string that is obtained by ...
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1answer
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What is the benefit to using a two-pass AE scheme rather than one-pass?

What benefit is gained using a two-pass AE or AEAD scheme rather than a one-pass? Two-pass is roughly half the speed.
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2answers
215 views

A method for securely sharing centrally-stored documents among a changing set of users?

I believe it's possible to meet these requirements only if a third party is involved in a manual process. For example: Each user is given the same public key The private key resides offline at a ...
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1answer
452 views

Secure implementations of G2/G3/G4 cellular technology

It appears that GSM is like any other technology, and is only as secure as its implementation. What implementations are known to be secure or insecure due to a fault on the implementor's side, or due ...
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Is this how to implement CTR around a system that only implements CBC, CFB, CTS, ECB and OFB?

The encryption library in my programming language does not support CTR, though it supports CBC, CFB, CTS, ECB and OFB. I'm assuming it is theoretically possible to securely implement CTR around one ...
9
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1answer
436 views

Optimal variable sizes in the Secure Remote Password protocol

I am implementing the Secure Remote Password protocol: U = <username> --> <-- s = <salt from passwd file> a = random() A = g^a ...
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3answers
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When using AES and CBC, can the IV be a hash of the plaintext?

[Originally on programmers.stackexchange.com with title: Can you encrypt with AES+CBC and search the encrypted data] Basically, I'm going to go with Advanced Encryption Standard with either ...
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Tool or Process to check for AES-NI support on processor?

In another question, Thomas' answer mentioned the AES-NI instruction set, which piqued my curiosity. Is there a tool or process available out there to check whether the instruction set is available ...
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1answer
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How to choose a stream cipher

Are there high-speed ciphers designed for things like internet streams without sacrificing security? There are so many options that operate in stream mode. How would one choose a cipher?
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Encryption strategies for multi users access in production systems

I am pretty unknown to encryption strategies in production environments. So my concern is to find a solution how to strongly encrypt data, but make it available to multiple users with different keys. ...
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3answers
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Using Secure Remote Password without sending the username in the clear

To initiate a key exchange using the SRP protocol the client sends the username so the server can look up the salt and password verifier. Is there a simple way to change this so that an evesdropper ...
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3answers
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How to estimate the time needed to crack RSA encryption?

How to estimate the time needed to crack RSA encryption? I mean the time needed to crack Rsa encryption with key length of 1024, 2048, 3072, 4096, 5120, 6144, 5120, 7168, 8192, 9216, 10240, 11264, ...
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6answers
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Security of SHA256 and Bitcoins

The Bitcoin network use SHA256 as a core component to it's design. I'm no expert on cryptography, but it seems to me it usually is only a matter of time before security vulnerabilities are discovered ...
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5answers
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Is there a digital “safety deposit box” equivalent?

Digital safety deposit boxes: do they exist? if yes, are (any|they) trustworthy? There are many bricks and mortar financial institutions where one can rent a locked box in a locked room and be ...
9
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2answers
556 views

How do you Secure VOIP in a large organization

As part of a large organization looking to implement VoIP, to get on the bandwagon of savings and converged network focus, I'm being asked to look at the security concerns to develop a policy to help ...
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2answers
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Simple way to encrypt files on Linux and decrypt on Windows?

We are in need of an encryption process for backups of very valuable data. This data will be stored on a distributed filesystem, so even with permissions set right, its not out of reach that this data ...
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2answers
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Are URLs viewed during HTTPS transactions to one or more websites from a single IP distinguishable?

For example, say the following are HTTPS URLs to two websites by one IP over 5 mins: "A.com/1", "A.com/2", "A.com/3", "B.com/1", "B.com/2". Would monitoring of packets reveal: nothing, reveal only ...
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3answers
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Is the OpenPGP private key inherently password-protected?

I know I am required to enter a password every time I use my OpenPGP key. Is this done via software implementation or is it a property inherent to the protocol, and therefore the key? Essentially, ...
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1answer
524 views

Help on interpretation of FIPS-140 paragraph

This is from the FIPS 140-2 standard: Cryptographic keys stored within a cryptographic module shall be stored either in plaintext form or encrypted form. Plaintext secret and private ...
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3answers
834 views

Are the encryptions “broken” with great computing power?

http://www.dwavesys.com/en/pressreleases.html#lm_2011 Lockheed Martin Corporation (NYSE: LMT) has entered into an agreement to purchase a quantum computing system from D-Wave Systems Inc. I'm ...
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3answers
718 views

Most widespread use of PGP after 20 years

Phil Zimmerman released PGP (Pretty Good Privacy) on June 5, 1991. As we examine the legacy of that far-sighted and brave act 20 years later, what are the most widespread and helpful uses of PGP ...
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2answers
512 views

General Question on FIPS requirements

I understand that FIPS addresses cryptographic operations. My question is, is it addressing exactly this? For example, can an application loading a keystore use a non-FIPS provider? Any input or ...
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3answers
1k views

Security implications of storing the password hash along an encrypted AES key

I am using the PKCS#5 standard to generate a key using a random and unique salt and the user's password in input. Consider this key as the "encryption" key. The "encryption" key is used to encrypt a ...
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PKCS#5 Salt privacy? [duplicate]

Possible Duplicate: Password Hashing add salt + pepper or is salt enough? In the official documentation of the PKCS5 V2.0 standard, we can read "The salt can be viewed as an index into a ...
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2answers
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How to store my contacts encrypted?

I use KeePass for storing my passwords. What should I use if I want to store my several hundred contacts (name, phone number, email, etc) encrypted?
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8answers
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How to determine what type of encoding/encryption has been used?

Is there a way to find what type of encryption/encoding is being used? For example, I am testing a web application which stores the password in the database in an encrypted format ...
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2answers
310 views

homomorphic encryption and DARPA

Why the government (and the DARPA in particular)is spending all these millions to improve the homomorphic encryption?which useful usage could it get?
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4answers
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What Partial Homomorphic Encryption implementations exist and how do I leverage them?

It appears that only Partial Homomorphic Encryption(P.H.E.) is practical for modern day (2011) use. However I'm having difficulty locating libraries (FOSS or otherwise) that enable me to leverage ...
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6answers
664 views

Primary Key as Salt?

Is it okay to use the primary key as the salt in a Users table? The only disadvantage that I can see is if the PK changes (unlikely), then the passwords break. What are your thoughts?
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3answers
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Which real time cross-platform chat applications exist with end-to-end encryption?

I am looking for an instant messaging / chat application which can be used securely across different platforms, eg Windows, Linux, BSD! Do any exist?
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1answer
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How do I learn Cryptographic/Mathematical notation

I asked a question earlier where it was recommended that I describe my issue using standard cryptography notation. How do I learn this notation and how to convey my approach? How can I annotate this ...
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1answer
1k views

Peer review of C# cryptography for Azure Table security

Edit: Update - I am researching how to implement AES with authentication in an efficient way for this project. If you have the time I'd appreciate your skill in finding the best implementation for ...
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4answers
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In what ways does Full or Partial Homomorphic Encryption benefit the cloud?

Can someone explain, in plain English, the practical ways FHE and PHE can be leveraged in the cloud? Some interesting (and confusing) links include this Microsoft Research PDF and this wiki entry. ...
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symmetric encryption session keys in SSL/TLS

This question concerns the session send and receive keys used in SSL/TLS protocol. my understanding is that this key uses symmetric encryption (DES, AES, BlowFish, etc.) I'm wondering, if ...
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Question about dictionary attacks on GnuPG symmetric encryption

They say algorithms like AES can't practically be broken given a long enough key length (> 128 bits). If I use GnuPG to encrypt a file using AES: gpg -c --cipher-algo AES secretfile it asks me for a ...
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2answers
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How does the padding scheme impact the security of encryption

After digging a little deeper into cryptography I am wondering what impact the different padding schemes do have an the security of an encryption algorithm. Lets take AES-128 in CBC mode as an ...
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1answer
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What is the value of encrypting a payload when it will be transferred over sftp anyway?

We have a integration arrangement to send content across the internet and the agreed protocol encrypts then sends it via sftp. What possible reason coould there be to encrypt the content twice? I ...
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3answers
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How to optimize compressed file cracking?

I'm currently doing research on cracking encrypted, compressed files (specifically: uif, zip, 7z, dmg). Looking at all the utilities out there, it seems the time it takes to crack something is ...
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2answers
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The new CCMP attack against WPA/WPA2 PSK

The use of Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) for WPA/WPA2 PSK is being attacked. This is a trivial attack (offline brute force) against the initial ...
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3answers
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Encrypting a fixed format message with commands and transmitting over the internet

Linked to: Encrypting a fixed format message? I need to communicate from Site A, a set of information that will be presented to users of Site A, which when they choose to submit, should travel to my ...
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3answers
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It is safe to buy a domain if I get this message in Firefox?

Greetings, I want to buy a domain name from a big registar(well known on the internet) but when I go to checkout I see that my link is going from full encrypted to “Connection Partially Encrypted” ...
2
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1answer
310 views

How to tell if Firefox Home (iOS) is using Data Protection API?

The source code is here: http://mxr.mozilla.org/services-central/source/fx-home/ What should I be looking/search for? Or even how to extract /ffhomeDB.sq3 and see what it contains.
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2answers
253 views

Is random data inserted into an encrypted stream easy to retrieve?

Given that I have two pieces of data: A large piece of encrypted data. A small, fixed-size piece of random data. I want to be able to transmit both pieces of data together, but I don't want the ...
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4answers
3k views

Is it feasible to encrypt customers personal data? (name, address etc…)

Seeing the Sony Personal data kerfuffle unfold has gotten me thinking about the encryption and securing of personal data - obviously credit cards can (and should) be encrypted, making data breaches of ...
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4answers
594 views

Possibility of undetectable encryption system

I am not sure if it is pre-mature to ask such a question. The question is largely inspired by pondering over the question and discussions in the following link (In his answer, @Dad also raises ...
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1answer
5k views

Feistel Block Cipher

Can anybody explain, in simple terms, how Feistal Block Ciphers work. I am not a math student so I do not understand the math behind it, just would like the principles.
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2answers
218 views

Encrypting a fixed format message?

I'm planning to send across TWO pieces of information over the internet from machine A A site identifier which will be like: $SiteName = "EXAMPLE" (in plaintext) Encoded text which will be like: ...
6
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4answers
552 views

What do you do to protect data on a Macbook in the event of theft/loss of the device?

What setup do you recommend to protect data on a MacBook in the event of theft/loss of the device? I'm specifically interested in Macs here, rather than laptops generally, and in concrete ...
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Thoughts on Tiny Encryption Algorithm (TEA, anyone)?

I'm planning to implement Tiny Encryption Algorithm and exchange data between two PHP sites. Specifically, using the code presented at PHP-einfach.de Does anyone have any experiences / thoughts / ...
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What are the good use cases for disk encryption?

I've been researching disk/file system encryption, and on the surface it seems like a good idea for a lot of things. But as I dig further, the security it offers seems more mirage like than real. ...