Kāpēc ilgāks laiks, lai dators varētu reaģēt uz nepareizu paroli pret pareizo variantu?

Satura rādītājs:

Kāpēc ilgāks laiks, lai dators varētu reaģēt uz nepareizu paroli pret pareizo variantu?
Kāpēc ilgāks laiks, lai dators varētu reaģēt uz nepareizu paroli pret pareizo variantu?

Video: Kāpēc ilgāks laiks, lai dators varētu reaģēt uz nepareizu paroli pret pareizo variantu?

Video: Kāpēc ilgāks laiks, lai dators varētu reaģēt uz nepareizu paroli pret pareizo variantu?
Video: HOW TO RESET/RECALIBRATE A LAPTOP BATTERY | Increase battery capacity UPTO 40% | - YouTube 2024, Aprīlis
Anonim
Vai esat kādreiz ievadījis nepareizu paroli savā datorā un pamanījāt, ka atbildes laikā tas aizņems dažus mirkļus, salīdzinot ar pareizo ievadīšanu? Kāpēc ir tā, ka? Šodienas SuperUser Q & A ziņai ir atbilde uz ziņkārīgo lasītāja jautājumu.
Vai esat kādreiz ievadījis nepareizu paroli savā datorā un pamanījāt, ka atbildes laikā tas aizņems dažus mirkļus, salīdzinot ar pareizo ievadīšanu? Kāpēc ir tā, ka? Šodienas SuperUser Q & A ziņai ir atbilde uz ziņkārīgo lasītāja jautājumu.

Šodienas jautājumu un atbilžu sesija mums priecājas par SuperUser - Stack Exchange dalību, kas ir kopienas vadīta Q & A tīmekļa vietņu grupa.

Ekrānuzņēmums pieklājīgi no sully213 (Flickr).

Jautājums

Lietotāja SuperUser lasītājs user3536548 vēlas uzzināt, kāpēc ilgāks atbildes laiks, kad tiek ievadīta nepareiza parole:

When you enter a password and it is correct, the response time is practically instantaneous. But when you enter an incorrect password (by accident or having forgotten the correct one), it takes a while (10-30 seconds) before it responds that the password is incorrect.

Why does it take so long (relatively) to say that the password is incorrect? This has always bugged me when entering incorrect passwords on Windows and Linux systems (regular and VM-based). I am not sure about Mac OSX since I cannot remember if it is the same (it has been a while since I last used a Mac).

I am asking in the context of a user logging in to the system physically on location rather than through SSH which could conceivably use somewhat different mechanisms to log in (validate credentials).

Kāpēc ilgāks atbildes laiks, ievadot nepareizu paroli?

Atbilde

SuperUser atbalstītājs Michael Kjorling mums ir atbilde:

Why does it take so long (relatively) to say that the password is incorrect?

It does not. Or rather, it does not take the computer any longer to determine that your password is incorrect compared to it being correct. The work involved for the computer is, ideally, exactly the same. Any password verification scheme that takes a different amount of time based on whether the password is correct or incorrect can be exploited to gain knowledge, however small, of the password in less time than would otherwise be the case.

The delay is an artificial delay to make repeatedly trying to gain access by using different passwords infeasible, even if you have some idea of what the password is and automatic account lockout is disabled (which it should be in most scenarios as it would otherwise allow for a trivial denial of service against an arbitrary account).

The general term for this behavior is tarpitting. While the Wikipedia article talks more about network service tarpitting, the concept is generic. The Old New Thing is not an official source either, but the article “Why does it take longer to reject an invalid password than to accept a valid one?” does talk about this (near the end of the article).

Vai kaut ko pievienot paskaidrojumam? Skatieties komentāros. Vēlaties lasīt citas atbildes no citiem tehnoloģiju savvy Stack Exchange lietotājiem? Šeit skatiet pilnu diskusiju pavedienu.

Ieteicams: