RSA numbers

September 3, 202666,114 views#24 that day New today

Large semiprimes created to challenge prime factorization research and computational number theory.

Why it's trending

via Google Search

RSA numbers, large semiprimes for factorization research, are trending after Eric Lu factored the 260-digit RSA-260—unfactored for 35 years—setting a world record.

More on why it's trending

Eric Lu announced the factorization of RSA-260, a 260-digit number that had stood unfactored for 35 years, setting a new world record for the largest general-purpose number factorization. The achievement sent curious readers to the Wikipedia article on RSA numbers to understand what these challenge numbers actually are.

Sources

  • johndcook.com
    New RSA number factored

    Eric Lu announced on X today that he has factored RSA-260, a number N with 260 digits (862 bits) that is the product of two large primes [1].

  • reddit.com
    RSA-260 factored : r/math

    The first RSA numbers generated, from RSA-100 to RSA-500, The value is the multiplication of two large prime numbers. RSA sets out an algorithym for securely ...

  • linkedin.com
    Craig A. Linton's Post

    RSA-260 is a "challenge number," not an encryption algorithm or key standard. RSA-240 and RSA-250, were solved in 2019 and 2020, respectively. RSA-260 is a 260 ...

  • explainx.ai
    RSA-260 Factored: Verify It Yourself in 3 Lines (2026)

    RSA-260 is a 260-decimal-digit, factoring difficulty. It had stood unfactored for 35 years. RSA-250, fell in February 2020.

  • x.com
    Silas Alberti on X

    This sets the world record for the largest general-purpose number factorization. The next-smallest number RSA-250 was factored in 2020.

  • tech.yahoo.com
    What's the tech behind the record-breaking RSA-260 crack?

    The three co-founded a company named RSA Security, and in 1991 it published a list of "RSA numbers," each formed by multiplying larger and larger secret primes.

  • facebook.com
    On Thursday technical researcher Eric Lu sparked ...

    RSA-260”—a number used for RSA, one of the world's most popular encryption schemes … number 2,269,753, which has 22 bits. However, modern RSA keys are much ...

  • shattered.io
    ECC vs RSA: 25x Faster Signing, Smaller Keys [2026]

    This piece breaks down what actually separates RSA from elliptic curve cryptography (ECC) in 2026: the math, the speed, the adoption numbers, the pricing, and ...

  • docs.espressif.com
    RsaMultiplication in esp_hal::rsa - Rust

    Support for RSA peripheral's large number multiplication feature that could be used to find the `operand a * operand b`.

Read on Wikipedia →
Nitty gritty details
ID
ee74a0e3-8db8-4395-8126-39f4aaa46cb4
Trending date
2026-09-03
Title
RSA_numbers
Normalized title
RSA numbers
Link
https://en.wikipedia.org/wiki/RSA_numbers
View count
66114
Rank
24
Mystery rank
29
Newly trending
true
View delta %
75029
Mystery
false
Topic
-
Country
-
Trending reason source
search
Search query used
RSA numbers
Prompt version
v2.5
Flag for test
false
Created at
2026-09-05T01:21:20.218374+00:00
View history (JSON)
[
  {
    "date": "2026-08-30Z",
    "views": 95
  },
  {
    "date": "2026-08-31Z",
    "views": 112
  },
  {
    "date": "2026-09-01Z",
    "views": 109
  },
  {
    "date": "2026-09-02Z",
    "views": 88
  },
  {
    "date": "2026-09-03Z",
    "views": 66114
  }
]
Raw search results
{
  "searchParameters": {
    "q": "RSA numbers",
    "type": "search",
    "autocorrect": false,
    "tbs": "cdr:1,cd_min:08/27/2026,cd_max:09/04/2026",
    "engine": "google"
  },
  "organic": [
    {
      "title": "New RSA number factored",
      "link": "https://www.johndcook.com/blog/2026/09/03/new-rsa-number-factored/",
      "snippet": "Eric Lu announced on X today that he has factored RSA-260, a number N with 260 digits (862 bits) that is the product of two large primes [1].",
      "date": "1 day ago",
      "position": 1
    },
    {
      "title": "RSA-260 factored : r/math",
      "link": "https://www.reddit.com/r/math/comments/1w5z8p4/rsa260_factored/",
      "snippet": "The first RSA numbers generated, from RSA-100 to RSA-500, The value is the multiplication of two large prime numbers. RSA sets out an algorithym for securely ...",
      "date": "1 day ago",
      "position": 2
    },
    {
      "title": "Craig A. Linton's Post",
      "link": "https://www.linkedin.com/posts/craigalinton_rsa-260-has-just-been-solved-is-encryption-activity-7501250208895422464-T4VL",
      "snippet": "RSA-260 is a \"challenge number,\" not an encryption algorithm or key standard. RSA-240 and RSA-250, were solved in 2019 and 2020, respectively. RSA-260 is a 260 ...",
      "position": 3
    },
    {
      "title": "RSA-260 Factored: Verify It Yourself in 3 Lines (2026)",
      "link": "https://www.explainx.ai/blog/rsa-260-factored-verify-it-yourself-2026",
      "snippet": "RSA-260 is a 260-decimal-digit, factoring difficulty. It had stood unfactored for 35 years. RSA-250, fell in February 2020.",
      "date": "1 day ago",
      "position": 4
    },
    {
      "title": "Silas Alberti on X",
      "link": "https://x.com/silasalberti/status/2095387095955374235",
      "snippet": "This sets the world record for the largest general-purpose number factorization. The next-smallest number RSA-250 was factored in 2020.",
      "position": 5
    },
    {
      "title": "What's the tech behind the record-breaking RSA-260 crack?",
      "link": "https://tech.yahoo.com/science/articles/tech-behind-record-breaking-rsa-130000322.html",
      "snippet": "The three co-founded a company named RSA Security, and in 1991 it published a list of \"RSA numbers,\" each formed by multiplying larger and larger secret primes.",
      "date": "12 hours ago",
      "position": 6
    },
    {
      "title": "On Thursday technical researcher Eric Lu sparked ...",
      "link": "https://www.facebook.com/ScientificAmerican/posts/on-thursday-technical-researcher-eric-lu-sparked-worldwide-excitement-and-confus/1462855262379408/",
      "snippet": "RSA-260”—a number used for RSA, one of the world's most popular encryption schemes … number 2,269,753, which has 22 bits. However, modern RSA keys are much ...",
      "position": 7
    },
    {
      "title": "ECC vs RSA: 25x Faster Signing, Smaller Keys [2026]",
      "link": "https://shattered.io/ecc-vs-rsa-2026/",
      "snippet": "This piece breaks down what actually separates RSA from elliptic curve cryptography (ECC) in 2026: the math, the speed, the adoption numbers, the pricing, and ...",
      "date": "8 days ago",
      "position": 8
    },
    {
      "title": "RsaMultiplication in esp_hal::rsa - Rust",
      "link": "https://docs.espressif.com/projects/rust/esp-hal/1.2.0-rc.0/esp32c6/esp_hal/rsa/struct.RsaMultiplication.html",
      "snippet": "Support for RSA peripheral's large number multiplication feature that could be used to find the `operand a * operand b`.",
      "date": "4 days ago",
      "position": 9
    }
  ],
  "credits": 1
}

Evaluations(2)

From eval_results matching this article's title (or normalized title) and trending date. Reasoning is shown in full.

  • Field

    trending_reason_short

    Score

    5

    Pass

    Yes

    Prompt version

    v2.5

    Created

    Sep 5, 2026, 1:23 AM

    9167fc70-8e44-4efd-9e4c-d691e461b2f0

    Reasoning

    Perfectly faithful to source material with accurate facts, avoids title mention, and delivers a clear 22-word summary capturing the core trending reason.
  • Field

    trending_reason

    Score

    4

    Pass

    Yes

    Prompt version

    v2.5

    Created

    Sep 5, 2026, 1:23 AM

    d7d81da1-c760-48dd-9a1e-77fd7825cff6

    Reasoning

    Explanation is relevant, well-grounded (all claims traceable: Eric Lu's announcement, RSA-260 as 260-digit challenge number, 35-year unfactored status, world record for general-purpose factorization all appear in search results), appropriately concise and formatted; minor deduction because the search results don't explicitly state that people went to Wikipedia to understand RSA numbers, making the final clause a reasonable inference but not directly supported.