"trapdoor function" meaning in English

{
  "etymology_text": "From the idea that it is easy to fall through a trapdoor but difficult to climb back out.",
  "forms": [
    {
      "form": "trapdoor functions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "trapdoor function (plural trapdoor functions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Cryptography",
          "orig": "en:Cryptography",
          "parents": [
            "Computer science",
            "Formal sciences",
            "Mathematics",
            "Computing",
            "Sciences",
            "Technology",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Mathematics",
          "orig": "en:Mathematics",
          "parents": [
            "Formal sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A function that is easy to compute in one direction but difficult to compute in the opposite direction (finding its inverse) without special information."
      ],
      "id": "en-trapdoor_function-en-noun-rWD5ZTpT",
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "cryptography",
          "cryptography"
        ],
        [
          "function",
          "function"
        ],
        [
          "compute",
          "compute"
        ],
        [
          "direction",
          "direction"
        ],
        [
          "opposite",
          "opposite"
        ],
        [
          "inverse",
          "inverse"
        ]
      ],
      "raw_glosses": [
        "(mathematics, cryptography) A function that is easy to compute in one direction but difficult to compute in the opposite direction (finding its inverse) without special information."
      ],
      "topics": [
        "computing",
        "cryptography",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "sciences"
      ],
      "wikipedia": [
        "trapdoor function"
      ]
    }
  ],
  "word": "trapdoor function"
}

{
  "etymology_text": "From the idea that it is easy to fall through a trapdoor but difficult to climb back out.",
  "forms": [
    {
      "form": "trapdoor functions",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "trapdoor function (plural trapdoor functions)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Cryptography",
        "en:Mathematics"
      ],
      "glosses": [
        "A function that is easy to compute in one direction but difficult to compute in the opposite direction (finding its inverse) without special information."
      ],
      "links": [
        [
          "mathematics",
          "mathematics"
        ],
        [
          "cryptography",
          "cryptography"
        ],
        [
          "function",
          "function"
        ],
        [
          "compute",
          "compute"
        ],
        [
          "direction",
          "direction"
        ],
        [
          "opposite",
          "opposite"
        ],
        [
          "inverse",
          "inverse"
        ]
      ],
      "raw_glosses": [
        "(mathematics, cryptography) A function that is easy to compute in one direction but difficult to compute in the opposite direction (finding its inverse) without special information."
      ],
      "topics": [
        "computing",
        "cryptography",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "sciences"
      ],
      "wikipedia": [
        "trapdoor function"
      ]
    }
  ],
  "word": "trapdoor function"
}