Questions tagged [decryption]

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Can someone tell me how to decrypt this code into an email address? [on hold]

How do you decrypt this into an email address ? Njg2MTYzNmI2MTdhNmY2ZTQwNjQ2NTZjNmY2OTc0NzQ2NTJlNjM2ZjZk
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18 views

Why is it important that determinant is not divisible by factors of the length of the alphabetical modulo

I am doing an assignment and I came across a question which asked "Why is it necessary when using modulo 26 to have a determinant which is not a factor of modulo 26. I have searched everywhere for ...
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solving chaochiper encoded test [on hold]

**the encrypted text is: UAMN PRUC LPLB IPLO UHXR DODN JSBI DCDK DAFK VJCM YYFA YHJU MULA **
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56 views

Known Plain-text Attack [on hold]

How can I find the known plain text P2 based on the given information? Assuming that the encryption is made using a common initialization vector and the mode used for encryption is OFB. ...
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4 views

tshark decryption fails on old OS but succeeds on new OS [migrated]

I have a pcap tracefile and private RSA key that should allow me to decrypt the HTTPS data in the pcap file. With the exact same pcap file, private key and tshark command, I find that decryption ...
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1answer
75 views

OpenSSL: How to maintain padding from encryption after decryption?

One of my professors mentioned in class that there is a way of using PKCS#7 padding to have the padding persistent after decryption. For example, if I encrypt a 20-byte file using ...
2
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1answer
90 views

“hex” vs. “base64” encoding when enciphering

Examining different implementations of encryption / decryption with cipher on Node.js, I paid attention that some implementations use hex encoding: ...
2
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0answers
61 views

Possible deciphering methods for the steganography on an old check? [closed]

This check was deposited in the 1930s, and it was issued by OCBL (an old bank in Singapore). The checks issued by this bank had an interesting feature - an obfuscated pattern printed on the back of ...
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1answer
37 views

Is it possible to find what is the random generated key if I know the plaintext and ciphertext? [closed]

Is it possible to find what is the key with only plaintext and ciphertext? For example, My plaintext is: hi My ciphertext is: 0x1db5
2
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4answers
152 views

Is an invulnerable code possible (including brute force attack)?

If I double encrypted a text with for example AES wouldn't it be invulnerable to bruteforce attacks due to the computer not knowing when it has reached the plain text? Plain text->1st layer of ...
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1answer
69 views

NaCl allows decryption with the same public key as for encryption

I followed the description here: Public-key authenticated encryption: crypto_box and created an example that encrypts a message with Bob's public key and signs it with Alice's secret key : ...
3
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2answers
200 views

Is this toy RSA demonstration flawed?

I want to present the basics of how RSA works to an audience of beginners in cryptography. The problem is that I am lightyears from being an expert. After reading about how RSA works in wikipedia, ...
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1answer
51 views

How secure is a 40 bytes hexadecimal string AES256 encrypted with 50 bytes random password

Problem Assume I have a 40 bytes hexadecimal ASCII string and a 50 bytes random password. ...
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0answers
51 views

Subexponential algorithms that apply only one of factoring and discrete logarithm?

Shor (quantum polynomial), Number Field Sieve (subexponential), Pollard rho (square root) all have both factoring and discrete logarithm over $\mathbb F_p^*$ variants. What are the subexponential ...
1
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1answer
54 views

Are there any asymmetric key encryption/decryption algorithms?

When it comes to encrypting some data (where data being something of a large size), symmetric key cryptosystem is predominant. Symmetric key algorithms like AES, DES, Blowfish, IDEA etc. are ...
3
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1answer
81 views

Cryptography on programming

In pursuit of understanding a randomly found topic I was interested in learning the connection between integer programming and cryptography and found Lenstra Jr.'s Integer Programming and Cryptography....
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1answer
226 views

Apple CryptoKit - Understanding its portability

I've been playing with Apple's CryptoKit (their effort to make their old CommonCrypto lib more modern and easy to use via Swift, their programming language). I'm interested to see how portable it is.....
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2answers
307 views

How to find the key of XOR encryption in Java?

I am trying to find the key of an XOR-encrypted string in Java. It is very probable that the key is eight characters long. I have the encrypted string. I do not understand how to go backwards and ...
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0answers
29 views

Does the oracle have to have access to the encryption key to the padding oracle attack to work (CBC & PKCS#7)?

Does the oracle have to have access to the encryption key to the padding oracle attack to work (CBC & PKCS#7)? I tried much to get a attach to work, but the oracle doesn't have access to the ...
9
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1answer
4k views

How long does it take to crack RSA 1024 with a PC?

Using an Intel Core i5 CPU, how long does it take to crack RSA using a key size of 1024 bit (generated using a secure key pair generation function)? Suppose for instance that we have thousands of ...