nothing-up-my-sleeve number

noun

A number which, by its construction, is above suspicion of having hidden properties; used in creating cryptographic functions such as hashes and ciphers.

Ask AI about this wordChatGPTClaudePerplexityGoogle AIGrok

Meanings

nounnothing-up-my-sleeve number (plural nothing-up-my-sleeve numbers)

plural nothing-up-my-sleeve numbers

  1. computingA number which, by its construction, is above suspicion of having hidden properties; used in creating cryptographic functions such as hashes and ciphers.

    The key schedule, however, expanding the key using an essentially one-way method, is more complex, with the binary expansions of both e and the golden ratio of "nothing up my sleeve numbers".

    2014 May 28, Mr. Ajay Bhaisare, “Data Protection Outsourcing of Cloud Data to Maintain Trust between Cloud Service and Data Owner Using RC5 Algorithm”, in IJCSMC, volume 3, number 5, page 608
    1 more example

    Anyway, they make the same point: “The BADA55-VPR curves illustrate the fact that 'verifiably pseudorandom' curves with 'systematic' seeds generated from 'nothing-up-my-sleeve numbers' also do not stop the attacker from generating a curve with a one-in-a-million weakness.”

    2017, Manul Laphroaig, PoC or GTFO

Origin

In reference to magic tricks in which the performer may have something concealed in a sleeve (or may demonstrate to the audience that they do not).

Full word history & related roots →
Cite this entry
APA

nothing-up-my-sleeve number. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/nothing-up-my-sleeve%20number

MLA

“nothing-up-my-sleeve number.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/nothing-up-my-sleeve%20number. Accessed November 5, 2026.

Chicago

WatkinsX Dictionary, s.v. “nothing-up-my-sleeve number,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/nothing-up-my-sleeve%20number.

Source: nothing-up-my-sleeve number on Wiktionary, CC BY-SA 4.0.