The xor–encrypt–xor (XEX) is a (tweakable) mode of operation of a block cipher.
- XEX-based tweaked-codebook mode with ciphertext stealing (XTS mode) is one of the more popular modes of operation for whole-disk encryption.
- XEX is a common form of key whitening.
- XEX is part of some smart card proposals.[1][2]
- Gmp_xor (PHP 4 >= 4.0.4, PHP 5, PHP 7) gmp_xor. I understand that decyphering involves recognizing patterns and that it would be possible to decrypt code that was encoded using XOR with the same key if there were enough samples to examine. XOR encryption is an ultimate encryption algorithm. It can't be be broken. It is used to.
- Reversible XOR encryption in PHP March 31, 2015 by funvn It took to make reversible XOR – encryption with the ability to embed the encrypted string in the URL.
@Nacereddine the 'password' is the key to encrypt/decrypt using XOR, and i'm asking how to do that 'get the original string'! – Br3x Nov 21 '11 at 16:40 @Crontab I felt it was too short to be a good answer. A function to encrypt/decrypt a string using XOR e source code This snippet submitted by Major_Small on 2005-01-27. It has been viewed 77519 times.
Xor Encrypt Decrypt Php
History[edit]
Encrypt Php Files
In 1984, to protect DES against exhaustive search attacks, Ron Rivest proposed DESX:XOR a prewhitening key to the plaintext, encrypt the result with DES using a secret key, and then XOR a postwhitening key to the encrypted result to produce the final ciphertext.[3] Hp j3680 installation software.
In 1991, motivated by Rivest's DESX construction, Even and Mansour proposed a much simpler scheme (the 'two-key Even–Mansour scheme'), which they suggested was perhaps the simplest possible block cipher: XOR the plaintext with a prewhitening key, apply a publicly known unkeyed permutation (in practice, a pseudorandom permutation) to the result, and then XOR a postwhitening key to the permuted result to produce the final ciphertext.[3][4]
Studying simple Even–Mansour style block ciphers gives insight into the security of Feistel ciphers (DES-like ciphers) and helps understand block cipher design in general.[5]
Orr Dunkelman, Nathan Keller, and Adi Shamir later proved it was possible to simplify the Even–Mansour scheme even further and still retain the same provable security, producing the 'single-key Even–Mansour scheme': XOR the plaintext with the key, apply a publicly known unkeyed permutation to the result, and then XOR the same key to the permuted result to produce the final ciphertext.[3]
Rogaway used XEX to allow efficient processing of consecutive blocks (with respect to the cipher used) within one data unit (e.g., a disk sector) for whole-disk encryption.[6]
Many whole-disk encryption systems – BestCrypt, dm-crypt, FreeOTFE, TrueCrypt, DiskCryptor, FreeBSD's geli, OpenBSD softraid disk encryption software, and Mac OS X Lion's FileVault 2 – support XEX-based tweaked-codebook mode with ciphertext stealing (XTS mode).
References[edit]
![Encrypt php files Encrypt php files](https://www.sourcecodester.com/sites/default/files/images/bethwel/sample.png)
- ^Barış Ege, Elif Bilge Kavun, and Tolga Yalçın. 'Memory Encryption for Smart Cards'. 2011.
- ^Emmanuel Prouff. 'Smart Card Research and Advanced Applications'. 2011, p. 201.
- ^ abcOrr Dunkelman, Nathan Keller, and Adi Shamir. 'Minimalism in Cryptography: The Even–Mansour Scheme Revisited'.
- ^Joan Daemen, Laboratorium Esat. 'Limitations of the Even–Mansour Construction'. 1992. doi: 10.1007/3-540-57332-1_46
- ^Craig Gentry and Zulfikar Ramzan. 'Eliminating Random Permutation Oracles in the Even–Mansour Cipher'. 2004.
- ^Rogaway, Phillip (2004-09-24). 'Efficient Instantiations of Tweakable Blockciphers and Refinements to Modes OCB and PMAC'(PDF).
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Xor–encrypt–xor&oldid=849596558'
Active2 years, 6 months ago
I am studying encryption. And I got a problem like this:
After I XOR plaintext with a key, I get a crypt, '010e010c15061b4117030f54060e54040e0642181b17', as hex type. If I want to get plaintext from this crypt, what should I do in PHP?
I tried convert it to string/int and after that take them to XOR with the key (three letters). But it doesn't work.
This is the code:
And this is the result:
This is the test-------------
PHP Notice: Uninitialized string offset: 29 in C: UsersAdministratorDesktoptest.php on line 210 PHP Stack trace: PHP 1. {main}() C:UsersAdministratorDesktoptest.php:0 PHP 2. xor_this() C:UsersAdministratorDesktoptest.php:239
Notice: Uninitialized string offset: 29 in C:UsersAdministratorDesktoptest.p hp on line 210
Call Stack: 0.0005 674280 1. {main}() C:UsersAdministratorDesktoptest.php:0 0.0022 674848 2. xor_this() C:UsersAdministratorDesktoptest.php:23 9
UBE^A►WEAVA►WEAV@◄WEARAFWECWB++++++++
This is zs$fs☺
Why? The 'UBE^A►WEAVA►WEAV@◄WEARAFWECWB++++++++' is the result, which I got trouble in my real work.
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3 Answers
Try this:
Basically to revert text back (even numbers are in) you can use the same function:
Peter Mortensen14.4k1919 gold badges8888 silver badges117117 bronze badges
One Man CrewXor Encrypt Decrypt Phpmyadmin
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lalalalalala
Based on the code above i created 2 functions to xor encode a JSON string using javascript and then decode it on server side using PHP.
!!! Important: If you will have characters different from ASCII(like Chinese, Cyrillic, Symbols..) in your JSON string, you must either write some code in PHP or JS to fix how these characters are encoded/decoded (ord/chr in PHP produce different results in comparison with JS charCodeAt/String.fromCharCode) or just base64_encode the JSON string and after that xor encode it.
Personally i use
xor_string(base64_encode(JSON.stringify(object)), 'xor_key')
in JS and on PHP side:PHP:
Javascript:
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