In contemporary life, every user has more or less accounts, and there are always a few nasty pop-up windows when you log in, especially verification codes. At least during the Spring Festival, many friends should look at the complex verification code and see that they are going crazy …
What is the significance of the verification code? What will the verification code look like in the future?
Why do I need a verification code?
Before explaining the verification code, we must first introduce a great bull who is beyond the age-British computer scientist Alan Mathison Turing, Alan Turing, he also has a more well-known title “the father of artificial intelligence”.
For his story, you can check out the movie “Imitation Game”, starring Benedict.
As early as 1950, Turing proposed the possibility of a “future computer” in a paper. He believed that the computer of the future would have “intelligence”. In view of the fact that intelligence is difficult to distinguish, Turing proposed An epoch-making verification method:
A machine is said to be intelligent if it can talk to humans (via telex equipment) and cannot be identified as a machine.
This is also called the “Turing test” by future generations, and it is also the main idea of distinguishing humans from robots.
The full name of the verification code is the Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA). It was developed by Louis Von Ann of Carnegie Mellon University in 2002. put forward.
We all know that whether a website or an app is built on a server, and the capacity and bandwidth of the server are limited, if a large amount of non-human traffic flows into the server, it will cause the server to overload and affect the use of normal users. These non-human traffic include both mechanically working robots and crawlers that crawl page information.
Just like buying train tickets during the Spring Festival this time, in addition to many of the fellow travellers who are as loyal to you as you are, there are also ticket grabbing robots, oxen with ticket grabbing scripts and major travel apps. The ability to grab tickets for the latter few is much stronger than a single ticket purchaser …
Therefore, developers must ensure the normal use of normal users, and this must first distinguish between humans and robots, the role of the verification code is this.
In addition, the verification code can also play the role of “confirmation”. It is determined by the one-to-one verification code that the secret operation is performed by myself.
Verification code is not once and for all
Like many technologies, verification codes have continued to evolve, from the earliest four digits + text, to later types of English, numeric operations, Chinese character recognition, picture recognition, simple semantic analysis, common sense questions and answers.
English + numbers
Picture content recognition
Q & A
Even harder are the verification code for voice calls, SMS verification codes, etc. It can be said that the difficulty of cracking is one step at a time.
sending text verify code
Behind these complex captchas, there is a continuous improvement of captcha cracking methods: from the earliest brute force cracking, OCR text recognition, collision recognition, to the most advanced Tensorflow deep learning recognition captchas, both parties are here. China constantly upgrades its combat effectiveness to achieve a spiral rise.
In fact, compared with the continuously upgrading verification codes, the verification code cracking technology has not made much progress in recent years. This is mainly because there are not many methods available to increasingly complex verification code crackers.
After getting a piece of verification code, the algorithm first needs to automatically extract the text in the verification code, and then to reduce the influence of the “noise element” in the verification code on the recognition algorithm, and then to split a single text element to extract the verification code. And in the case of different fonts and interference noise, recognition accuracy and time constraints, it is difficult to develop a universal cracking algorithm.
But for traditional verification codes, the crackers still have a final trick-human coding, there are many coding platforms on the Internet, and someone will come over to code manually after posting a task, which is equivalent to using humans to cheat. The method passed the Turing test.
However, you must pay attention that such coding part-time platforms are basically fake. It is troublesome to pay the labor by coding, and it is troublesome to withdraw cash. In addition, some platforms will charge dirty money such as “handling fees” first. Everyone Do n’t be fooled, I ’ve suffered from beatings from the society when I was in college, and I lost hundreds of dollars.
New technology at the push of a button
Although the complex verification code does not need to worry about the attack of the cracking algorithm, it is a kind of torture for normal human users. Here I personally “commend” Samsung Cloud’s verification code, which can cancel my use power.
Therefore, in the mobile era, verification codes that reduce input and mainly rely on interactive operations such as clicking and swiping have become the verification codes that best meet user habits. At present, the slider-type verification code and the picture element recognition-type verification code are the main verification codes of major websites.
However, the best verification code service currently available is from noCAPTCHA launched by Google in 2014. The literal translation is “verification code without verification code”. It has been used for quite some time now. It will pop up, users just need to click the white square in front of “I’m not a robot” to complete the verification. The whole process takes only a few seconds, and no authentication is required to complete the verification.
Behind the simpler, Google ’s risk analysis engine is at work. This engine analyzes whether the user is a real person before, during, and after clicking on the verification code. This engine uploads the user ’s IP, country, and click time. , Mouse trajectory, web page scrolling records and other user usage conditions to the server, and then analyze whether the user’s real identity is human or robot.
At present, there are some imitators in this technology.
Although the verification code was born less than ten years ago, it has become one of the most important guardians of the network world. For users, verification codes are somewhat annoying, but with the continuous advancement of technology, verification codes are also becoming insensitive. Compared to buying train tickets with ticket-grabbing software, everyone seems to be “fair competition” under the same verification code.