Where does this come from, and can I check it?

Claude Shannon proved in 1949 that a random key used once gives a ciphertext compatible with every possible message. The figure is taken from Britannica, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a technology fact?

Yes. It sits on the Technology shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

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The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

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A one time pad cannot be broken by analysis

Claude Shannon proved in 1949 that a random key used once gives a ciphertext compatible with every possible message The pad must be truly random, as long as the message and never reused, and then any plaintext of the right length could have produced the intercepted text. That means no amount of computing power helps, because the ciphertext alone carries no information about the message. The difficulty is distributing and destroying the pads safely. It sits in Mondo's technology collection, one of 200 facts that each trace back to the reference below.

Where this comes from

Britannica

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Two strangers agreed a secret key in publicThe 1976 Diffie-Hellman method lets both sides derive the same number without ever sending it RSA made public key encryption practicalRivest, Shamir and Adleman built a system in 1977 whose security rests on the difficulty of factoring large numbers Colossus was the world's first programmable electronic digital computerTommy Flowers built Colossus at Bletchley Park in 1943 to break Lorenz cipher messages AES replaced a twenty five year old cipherNIST chose the Rijndael design in 2000 after a public competition, and it became the federal standard in 2001 Hamming codes find and fix a single bad bitRichard Hamming's 1950 scheme adds overlapping parity bits so a receiver can locate one flipped bit and repair it Reed-Solomon codes keep scratched discs playableIrving Reed and Gustave Solomon published the maths in 1960, and it now protects CDs, QR codes and deep space links

Tags: encryption, information-theory, cryptography

A one time pad cannot be broken by analysis: the short answers

Where does this come from, and can I check it?: Claude Shannon proved in 1949 that a random key used once gives a ciphertext compatible with every possible message. The figure is taken from Britannica, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a technology fact?: Yes. It sits on the Technology shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.