A one-time pad is an encryption method that uses a key (the pad) that is as long as the message. It provides perfect secrecy but at the cost of having as much key data as payload. Not to be confused with one-time passwords.

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Best practices for usefully storing two factor authentication backup codes?

For a lot of web services offering two factor authentication, after setting up the system, you are given a short list of backup codes (one-time pads) that are around 7-10 characters long. These are ...
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How to cryptoanalyze a one time pad that uses a plain text document as the pad?

I have read that in order for a one time pad to be truly secure, the pad itself must be random data. Given the practical difficulty of sharing a secure random pad, I was wondering what would be the ...
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Is breaking a looping one-time pad practical? If so, how?

A one-time pad is known to be theoritcally secure, nothing can break it. However, if the key is reused, the one time pad becomes theoritically breakable. But even RSA is theorically breakable yet ...
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How to fix this broken crypto protocol?

I am considering a protocol where you upload a one time pad to a server, using public key encryption and then the result (using the pad) is sent back in plaintext: Alice uses Bobs RSA public key to ...
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Advantages of one time pad

I always hear that one time pad'ing something is so great because you won't know if you've successfully decrypted the data. I understand the idea that you can XOR any bits just the same as any other ...
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Are there any systems out there that use a one-time pad?

I'm still new to information security, but I have read a bit about the one-time pad. The point that sticks out to me the most is that it is supposedly unbreakable. Has this method of encryption ever ...
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How strong is this encryption? [closed]

Given Dictionary containing 1000 three-letter words: dictionary=abc,def,ghi,jkl,mno,pqr... Randomly chosen words from the dictionary: 10-bits-passwords=abc,def,ghi Randomly chosen three words from ...
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How to Encrypt Credit Card number for storing it in sql server database according to PCI DSS Requirement?

According to PCI-DSS 3.4 Requirement: Render PAN unreadable anywhere it is stored by using the below methods: One-way hash Truncation Index tokens and pads Strong cryptography with associated ...
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One time pad encryption

Hello all I have a question about OTP encryption. I understand that one of the requirements (and a major drawback) of OTP is that the key has to be as long as the message is. What happens if i have ...
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What is (“ASCII” redundancy) which is said to be required to retrieve the original plain text in 2 times pad?

Sorry for the long title :$ In a video speaking about attacks on the one time pad which uses psudorandom generators (PRG), It's said that Eve can retrieve the plain text of 2 messages that have been ...
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An attempt to overcome the key distribution problem inherent in one time pad cryptography

After reading about the 'imminent cryptocalypse' etc, I started thinking about a cryptographic protocol that would not depend on complexity of mathematical operations (e.g. factorisation, discrete ...
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Is using a numbers station to transmit a one-time-pad as key actually insecure?

We all know the two most important problems related to a “one-time-pad”: The one-time-pad needs to be truly random (which I think is logic, as pseudo random generators are quick but predictable). ...
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Decrypt cipher texts encypted with the same one time pad key

I have two pieces of ciphertext encrypted with a stream cipher using the same key. How do I recover the plaintext of both ciphertext messages without knowing the key used?
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Why is using a pseudo-random key considered more practical than a one-time pad?

I am experiencing confusion regarding one-time pads. I have read that a one-time pad generates a key that has the same length as the plaintext. This is considered to be an overhead in sharing such a ...