It's the first idea I had when it came to making sure login on my server is secure. Instead of having a small password that relies on my fallinble memory and may be also guessed in a not-completely-rodiculous amount of time.
Meanwhile a fairly small file, something like a 512 byte "user.key", to be uploaded along with your username, or even just having your username built-in, seems much safer.
I wanted to do some math but I could only find limited calculators for doing calculations with such big numbers so have the amount of possible combinations the file may have:
256^512
1,044,388,881,413,152,506,691,752,710,716,624,382,579,964,249,047,383,780,384,233,483,283,953,907,971,557,456,848,826,811,934,997,558,340,890,106,714,439,262,837,987,573,438,185,793,607,263,236,087,851,365,277,945,956,976,543,709,998,340,361,590,134,383,718,314,428,070,011,855,946,226,376,318,839,397,712,745,672,334,684,344,586,617,496,807,908,705,803,704,071,284,048,740,118,609,114,467,977,783,598,029,006,686,938,976,881,787,785,946,905,630,190,260,940,599,579,453,432,823,469,303,026,696,443,059,025,015,972,399,867,714,215,541,693,835,559,885,291,486,318,237,914,434,496,734,087,811,872,639,496,475,100,189,041,349,008,417,061,675,093,668,333,850,551,032,972,088,269,550,769,983,616,369,411,933,015,213,796,825,837,188,091,833,656,751,221,318,492,846,368,125,550,225,998,300,412,344,784,862,595,674,492,194,617,023,806,505,913,245,610,825,731,835,380,087,608,622,102,834,270,197,698,202,313,169,017,678,006,675,195,485,079,921,636,419,370,285,375,124,784,014,907,159,135,459,982,790,513,399,611,551,794,271,106,831,134,090,584,272,884,279,791,554,849,782,954,323,534,517,065,223,269,061,394,905,987,693,002,122,963,395,687,782,878,948,440,616,007,412,945,674,919,823,050,571,642,377,154,816,321,380,631,045,902,916,136,926,708,342,856,440,730,447,899,971,901,781,465,763,473,223,850,267,253,059,899,795,996,090,799,469,201,774,624,817,718,449,867,455,659,250,178,329,070,473,119,433,165,550,807,568,221,846,571,746,373,296,884,912,819,520,317,457,002,440,926,616,910,874,148,385,078,411,929,804,522,981,857,338,977,648,103,126,085,903,001,302,413,467,189,726,673,216,491,511,131,602,920,781,738,033,436,090,243,804,708,340,403,154,190,336
What am I missing? I assume I'm missing something, because the idea of something like this going over a lot of smart programmers and developers' heads does not sound right
mTLS (mutual TLS) is actually quite common out there. And SSH certificates moreso than public keys.
So clients get issued certificates that they can authenticate with. TLS for HTTPS but both ways. It sounds like this is what you're asking about?