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Questions tagged [128-bit]

Referring to computer architecture with addresses and other data units 128 bits wide.

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IV undefined Error while decrypting AES encrypted video

I am trying to decrypt AES 128 encrypted video with AES key and IV For decrypting I am using openssl key —î¡ŒØËÉްʾC{]5q)pZE4d4:-MBB¬vóRJ”7–Æ­‹5•Õ IV 0x496daa1c6914000e408c65cead91fc29 following is command line to decrypt video openssl enc -nosalt…
Shridhar Salunkhe
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128 bit floating point binary representation error

Let's say we have some 128bit floating point number, for example x = 2.6 (1.3 * 2^1 ieee-754). I put in in union like this: union flt { long double flt; int64_t byte8[OCTALC]; } d; d = x; Then i run this to get it hexadecimal…
DLWHI
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Correct way to sum 128bit numbers represented by 4 32bit unsigned integers?

I'm creating a kernel in C++ / CUDA in which I need to sum two 128bit numbers represented as follows: struct Int128 { unsigned int bit0_31; unsigned int bit32_63; unsigned int bit64_95; unsigned int bit96_127; }; Int128 sum(Int128…
Frax
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I want to perform Multiplication and Division of two 128 bit unsigned integers in a system that doesn't contain floats

Currently I am facing a problem where when I multiply two numbers 5e20 * 5e20 = 2.5E41 it overflows from 128 bit max range that can only contain a maximum number with 39 digits. So I cannot multiply two very big numbers due to which my precision is…
Saad Tahir
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How to implement binary128 in C?

I started to try and implement new data types, specifically floating-point values, using C. I came up with this sort of way on implementing binary128 using longer_int which I haven't fully understood. The way how I started was to implement it via…
user14793609
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Just want to decode the code into plain text

We would like to know more about function get_rnd_iv() and md5_encrypt() these function for using 128bit encoding. Now here we just want to know how to decode that code into plain text... Here is my all code lines.. function…
PPS
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How to encrypt String using Camellia 128-bit Encryption Algorithm in Java?

Im currently trying to develop a chat application that implement Camellia 128-bit as its encryption algorithm. I succesfully build and run the code from it official page [here][1]. The problem is the algorithm encrypt for Integer datatype. When im…
random peeps
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Generate 128 bit Poisson distributed numbers in cpp

I try to measure probabilities in the order of 1e-25 or even lower. I run a cpp code which is basically an ODE solver numerically (with simple Euler steps). I have long long ints for storing the cell numbers (every step I roll a dice and I update…
Demeter Márton
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LLVM: Make LLVMFP128Type from long double

In LLVM, there is a LLVMFP128Type, though I cannot seem to find out how to convert an actual long double into a LLVMValueRef of type LLVMFP128Type directly. I can do the following (with a double): LLVMValueRef var = LLVMBuildAlloca( builder, …
Dosisod
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Why is C#'s decimal type 128 bits?

Is there a reason why C#'s decimal type was chosen to be 128 bits? Analogy with double would have suggested 64 bits (only decimal floating-point instead of binary), whereas analogy with Java, or a philosophy of 'make sure it has whatever it takes',…
rwallace
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Where does the SIMD instruction intermediate result store?

In Intel Intrinsics, you may find such instructions: _mm256_mullo_epi64 In the description: "Multiply the packed 64-bit integers in a and b, producing intermediate 128-bit integers, and store the low 64 bits of the intermediate integers in dst.", it…
Tio Plato
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PHP : openssl_encrypt result 32o string with 16o input string

I have a problem with the openssl_encrypt function. In aes-128-cbc, why function return a 32-bytes string with a 16-bytes string as input? Sample : $binaryK0 = openssl_encrypt(hex2bin("00000000000000000000000000000000"),"AES-128-CBC",…
laurent MENARD
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How to identify my AES encryption is 128 or 256?

Good day, I have a existing AES encryption java class in my workspace, however, I would like to know its using 128 or 256, I tried to google it but still unable to get it, the following is the code: static { AesKeyCipher aesKeyCipher = new…
Panadol Chong
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How do you modulo 128 bit struts in c?

I have a c struct as typedef struct u128b { uint64_t hi, uint64_t lo } u128b How would I perform a modulo expression x^e mod m when all 3 variables, x, ė, and m are all u128b structs? I've attempted to run the code from…
Mark
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Calculating quotient of (64bit unsigned integer) * (64bit unsigned integer) divided by 2^64

I want to calculate quotient of "multiplication of two 64bit unsigned integer" divided by 2^64. Some people says that 128bit integers are able to use, but in some programming language or some platform (like visual studio c++) doesn't support 128bit…
square1001
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