Encryption is the process of transforming plaintext using a cipher into ciphertext to make it unreadable to anyone except those possessing the key. Decryption is the process of transforming that ciphertext back into plaintext, using the key.

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How to use modes of operation in DES?

How to use modes of operation in block cipher with Data Encryption Standard (DES) ? How the Feistel structure properties are achieved in DES when a mode of operation such as ECB is used?
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41 views

Ideal way to profile/performance-measure cipher implementations

I have implemented a bit-sliced version of two ciphers (Gibbon-120 and Hanuman-120, both part of the Primates family of ciphers: http://primates.ae/wp-content/uploads/primatesv1.02.pdf ) I now want ...
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1answer
33 views

How do I decipher a text using a repeating one-time pad?

I have an encrypted message that is 582 characters long. I know that: It is in hexadecimal It has been encrypted using a one time pad The pad's length is exactly 50 characters When the pad reaches ...
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2answers
52 views

What makes an open source encryption algorithm safe?

Take for example the popular AES algorithm where we have a combination of substitution, shift row, mix column, and add key steps involved in encrypting plain test. All of the mathematical operations ...
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3answers
135 views

Any benefit to writing a message as a mix of 2 languages before encryption?

For example, imagine a message that is a mix of Japanese and English words; Japanese in unicode, English in ASCII. Japanese doesn't use spaces between words. The sentence structures, anything ...
3
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0answers
20 views

How to decrypt the below encrypted messages? [on hold]

My friend was experimenting with the encryption methods (self-made) to encrypt text using ASCII map. He wanted to try this idea whether this encryption can be broken and so shared an encrypted text ...
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0answers
53 views

Explanation of cryptographic terminology for newbies [on hold]

I feel like I'm making a mountain out of a molehill here, but I have (what should be) a relatively simple project, but the terminology used all over the Internet is either too simple or too difficult ...
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1answer
111 views

Is the use of AES in LoRaWAN correct?

I'm reading about LoRaWAN (specification). This network protocol has a particular way to encrypt data, detailed in the part 4.3.3.1. Here is a recap of how the encryption work, as I understood it. ...
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2answers
185 views

Verifying Without Knowing Key

Say user Bob sends an encrypted message to a server. People can download the message from this server and later get the key directly from Bob. Is it possible for the server to somehow verify that ...
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1answer
35 views

Given C is a code of length n. Containing M code-words with a distance d

I'm studying for my exam and came across this question below. I don't understand how to get $d$. I get $C$ is a code of length $n$. Containing $M$ code-words with a distance $d$. $(n,M,d)$ But how ...
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1answer
82 views

Salting Hash stored on RFID tag?

In my application, I am trying to prevent counterfeit widgets from being used on our gadgets; think HP ink-cartridges. I will be doing such with UHF RFID tags embedded in the widgets. Unfortunately, ...
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3answers
3k views

How to check the strength of an encryption algorithm?

I asking for advice on how to check strength of an encryption algorithm.
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3answers
552 views

Did non-military cryptography appear in 50's and 60's only due to NSA leaks?

I'm not talking about scytale, but encryption like RSA, DES, etc... How did exactly civil cryptography evolve after World War II?
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1answer
27 views

Can I use the Sequence Number as the (implicit) IV in AES-GCM IPsec?

The RFC https://tools.ietf.org/html/rfc4106#page-5 states that, under AES-GCM IPsec, each packet is expanded by 8 bytes for the IV and up to 16 bytes for the ICV. Why? Since we already have a ...
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0answers
55 views

NSA Suite B revoked [closed]

NSA Suite B was formerly documented in CNSSP-15 "National Information Assurance Policy on the Use of Public Standards for the Secure Sharing of Information Among National Security Systems". NSA has ...
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5answers
31k views

Can you help me understand what a cryptographic “salt” is?

I'm a beginner to cryptography and looking to understand in very simple terms what a cryptographic "salt" is, when I might need to use it, and why I should or should not use it. Can anyone offer me a ...
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0answers
24 views

What is the best approaches to find the type of a Cipher / Encryption? [duplicate]

There are many known and unknown encoding and encryption types / algorithms. When the algorithm is known, then at least it gives some direction or approach on what to do next to obtain the plaintext ...
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1answer
65 views

Key Hierarchy and key Encryption

If i have two 56-bit DES keys, and I use these two key to encrypt a 256-bit AES key. Like this $K_{AT}$ encrypts $K_{BT}$ and $K_{BT}$ encrypts $K$ What is the effective security of key $K$? Is it $...
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2answers
7k views

How does order-preserving encryption work?

Order-preserving encryption (OPE) is, apparently, a method of encrypting data so that it's possible to make efficient inequality comparisons on the encrypted items without decrypting them. I've been ...
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1answer
26 views

Secure Cipher Suites supported by JDK versions [closed]

I'm a n00b to cryptography. I've been searching through oracle's java docs, ssl labs, googling and more googling attempting to find an up to date list of cipher suites considered secure for the ...
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5answers
231 views

Is it better to encrypt before compression or vice versa?

Is it better to encrypt a plain text file before compression, or vice versa?
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0answers
74 views

Security of Fernet Construction (wrt non self delimiting tokens and HMAC short key size)

Fernet is a described as a "high level symmetric encryption recipe" (source) that seems to be the default high level encryption scheme in the cryptography python ...
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0answers
26 views

Error Detection/Correction Code-Then-Encrypt

I've just studied about the error correction schemes and encryption. First rule when using EDC/ECC is to first encrypt and then calculate them, and the major motivation we were told is that "EDC/ECC ...
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1answer
119 views

Using e-ID Number for Encryption and Digital Signing

I want to use e-ID number for performing Encryption/Decryption and Digital Signing - and in order to do so, I've opted a PGP-oriented approach which goes a bit like this. Generating PGP key-pair ...
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0answers
18 views

C# to PHP partially decoded string [closed]

Hello I am trying to send data from c# application to my webserver. And I got like 99% of data decrypted right now the use of URI.encode helped me a lot to increase sucessfull decryption by many %. ...
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10answers
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Are there any advantages in using proprietary encryption?

Proprietary software generally relies on the fact that in keeping the encryption algorithm private, it gets an extra layer of security implying "Security through Obscurity." Obviously this phrase has ...
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15 views

How much bandwidth is used in a typical IKE/ISAKMP initialization?

How much bandwidth is used in a typical IKE/ISAKMP initialization? How many UDP packets are sent in each direction, and what is their typical size? I'm referring to initialization of IPsec via IKE/...
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1answer
39 views

what kind of custom header add to encrypted file to identify my encryption,consider safe and reliable.like pseudo format extension or file size

I want to add some custom header to encrypted file to identify my encryption,consider safe and reliable.like pseudo format extension or file size.Is there any algorithm or tool to make it?
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3answers
171 views

Encryption-then-encode or encode-then-encryption?

I have this question in which I m struggling. I have read in many sites about encrypt-then-mac etc. If the confidentiality for transmission is needed, discuss the feature for the order of encryption ...
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2answers
57 views

Security (CPA?,CCA?) in Authenticated identity-based encryption

When I read authenticated identity-based encryption by Ben Lynn, encryption works to send data from user A to user B where: $$a=e(d_{A},B)$$ $$s=H_{3}(Msg,K)$$ $$C=<s,\gamma \oplus H_{2}(a,s),H_{4(...
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LENGTH Parameter in the EEA2 AES-128 of LTE

In the EEA2 option for encryption in LTE the AES-128 algorithm is mechanized. There, the nonce used in the CTR Mode is a 128-bit value. The first 64-bits are covered by a COUNTER, a BEARER, a ...
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23 views

Decryption of fields in MS Access DB [closed]

I want to interact within my c# app with another programs database. this is stored in Microsoft Access format. But thats not the point. There are some fields whose content is encrypted, and i don't ...
3
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1answer
59 views

What would currently make the strongest https connection?

when you look at the encryption websites use you will see that there is alot of diversity, some use 256 bit keys some do not, some use DHE-RSA some ECDHE some use sha 256 some sha1, but my question is,...
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1answer
81 views

Why does 3DES need private key to decrypt?

I create two files, my.cer and my.pem ( include certificate and private key), I encrypt a file with my.cer, I use openssl smime -encrypt command. When decrypting data, it needs my.pem. I think 3DES ...
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1answer
56 views

Does encryption of data/information take place in peer to peer networks like Gnutella, Bittorrent?

Do peer to peer networks like Gnutella, Bittorrent have any encryption system to secure the users privacy or encrypt the file/data being shared? Elaborate please.
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1answer
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bruteforce on aes 256 cbc mode

i have a series of encrypted text , they encrypted by aes 256 bit cbc mode for every encrypted text there is an iv that i have them also and i know its algorithm is aes 256 bit cbc mode i can ...
3
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2answers
145 views

Should I add randomness at the end before AES?

Seen AES, changing a character drastically affects the encrypted text. I want to make it harder to decrypt AES I send. So, it seems this can be done by adding some special code and some random bytes <...
2
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1answer
51 views

Application level encryption and key renewal

I had posted this question on stackoverflow and been asked to move it to crypto. What is your view on this? What is the doability? I have a question related to encrypting data in the database, at the ...
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1answer
33 views

How to select a good scale for letter frequency in a text?

I needed to use a scale in a code to determine which sentence in a file has been encrypted by a single-character key. The scale that i currently used is: +2 for every occurrence of a vowel or a ...
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0answers
44 views

How to encrypt huge data using RSA? [duplicate]

Is there any way to encrypt the huge amount of data using RSA? I was supposed it is possible but when I read some articles what I saw is that, this is bad practice or they say can only encrypt bit ...
3
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1answer
66 views

How can I create pre-determined encrypted results?

I want my encryption results to be the lyrics to Star Spangled Banner. The original text I'm encrypting would be, for instance, the menu to a local pizza place. I know what I want my passphrase to be. ...
2
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1answer
72 views

Exponential cipher theory misunderstanding

Say I pick modulus $m=2633$ and key $e=13$ My private key $d$ is $13$ inverse in $\bmod 2632$ which I need to compute $(e,m)$ is my public key that anyone can use to encrypt message for me and then ...
2
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1answer
207 views

Mathematical formula for switching the key for OTP?

Instead of generating the random key for the one time pad cipher over and over again, is there a mathematical formula that allows you to switch the key to a new key? The new key must be as random and ...
2
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6answers
2k views

How secure will this be against brute-force attacks?

I'm looking into encrypting files like this: First, I SHA-1 hash the password. Let's say the password is something normal like "hello123", and then hashed. Then I encrypt a file using this: ...
20
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6answers
4k views

Did a certain cryptography method get abandoned due to security flaws in the past?

I am researching how quantum computers affect current encryption methods (RSA and more). However, I remember learning in a course that there used to be a particular encryption method which was ...
3
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0answers
1k views

Cryptography behind the Turing Imitation Key (TIK)

When browsing the internet I found out about this amazing phone. Well, it would be amazing if it was actually obtainable. It's called the Turing Phone, and it is supposed to come with as good as ...