In computer security, shoulder surfing is a type of social engineering technique used to obtain information such as personal identification number, password and other confidential data by looking over the victim's shoulder. This attack can be performed either from a closer range by directly looking over the victim's shoulder or from a longer range by using a pair of binoculars. To implement this technique attackers do not require any technical skills, keen observation of victims surroundings and the typing pattern is sufficient. Crowded places are the more likely areas for an attacker to shoulder surf the victim. In the early 1980s, shoulder surfing was practiced near public pay phones to steal calling card digits and make long distance calls or sell them in the market for the cheaper prices. However, the advent of modern-day technologies like hidden cameras and secret microphones makes shoulder surfing easier and gives more scope for the attacker to perform long range shoulder surfing. A hidden camera allows the attacker to capture whole login process and other confidential data of the victim, which ultimately could lead to financial loss or identity theft.
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Occurrences
Shoulder surfing is more likely to perform in the crowded places because it is easy to observe the information without dragging the victim's attention. Various situations where an attacker can easily shoulder surf the victim are, while filling out a form(bank withdrawal, deposit form or a loan form), entering their PIN at an automated teller machine or an at a POS terminal, using their telephone card at a public payphone, entering their password at a cybercafe, public and university libraries, or airport kiosks, entering their code for a rented locker in a public place such as a swimming pool or airport, entering their PIN or password on their smartphone.
A survey of IT professionals in a white paper for Secure found that:
Prevention
Some automated teller machines have a sophisticated display that discourages shoulder surfers from obtaining displayed information. It grows darker beyond a certain viewing angle, and the only way to tell what is displayed on the screen is to stand directly in front of it. Although this prevents an observer obtaining some information, e.g. account balance, it is generally not required to protect the PIN, because the PIN is typically not displayed during entry.
Certain models of credit card readers have the keypad recessed, and employ a rubber shield that surrounds a significant part of the opening towards the keypad. This makes shoulder-surfing significantly harder, as seeing the keypad is limited to a much more direct angle than previous models. ISO 9564-1, the International Standards for PIN management, describes such measures thus:
POS terminals often available in shops, supermarkets, and filling stations are more difficult to use in a way that prevents shoulder surfing as they are often located in exposed view on counters.
While making transactions, making sure to sit against the wall to prevent anyone to look into the system. Being careful about the environments, as there will be video cameras too. Using privacy screen protectors on the systems like the way bankers use to blank out the screen to others except our-self. Using one hand to cover the keypad while entering the pin at ATM. Being careful about the surroundings. Better not to access to personal accounts when in public. If in a crowded place, locating for a quiet place to work. Not revealing the passwords to anyone.
The awareness to the users at the public ATM can be provided while a shoulder surfing is occurring. Then a decision can be made by the user if the information he is entering in the public is sensitive and if it has to be hidden. Flashing border can be used to notify and alert the user. When a person enters the area near to the user, the borders of the machine flashes by alerting the user. It can even be detailed with colors. Like red color can be used if the person entered is looking towards the display and green when the person is still near that vicinity but not looking towards the display. Another way is creating a 3-D shadow on the display of the user peeping into the display.
While making important pecuniary transactions, making sure to be far from the people. These crimes are not well recorded as many of the people are not reporting to the police. Do not reply to phishing e-mails and even to the pre-texting phone calls. No bank or financial companies will ask for sensitive information through calls or e-mails. Avoid mailing the sensitive information. If ever there is a situation to send the financial documents, send them through certified mailing institutions and make sure to have a proof that the financial institution has received all the documents. If the account has already been compromised, immediately stop all the transactions to that account
Being cautious at the ATM
While using the ATM, it is recommended to stand close to the machine while entering the details. As already mentioned in the above, it is better to shield with the hand while entering the pin on the keypad. Sometimes, there may be a camera that is fixed near the keypad to record the actions being done on the keypad. If the ATM that is being used is in a crowded place and if there is someone who is trying to trace, it is better to stop the transactions at that ATM and leave. Never take any help from the strangers though they look well-mannered. Never get being distracted. People sometimes fix devices that record all the card details. These details are later used by the one who fixed the device by making fraud transactions. When in such situation, call to the card banker and report the issue while being still near the ATM. It is always a better thing to save the bank’s 24/7 customer service number. After a transaction, the very first thing to do is, always get the money and the card in the bag. Do not just throw the ATM receipts in the trash. Always tear them or at least destroy the sensitive information on the receipts. Never write the checks in a hurry. It is better to avoid writing checks at the peek time of the shopping season. Using only one card for shopping is sometimes better which not only helps in monitoring the money spent, but can also be easy to know the suspicious activity on the other accounts if happened.
Gaze-based password entry
The basic procedure for gaze-based password entry is similar to normal password entry, except that in place of typing a key or touching the screen, the user looks at each desired character or trigger region in sequence (same as eye typing). The approach can, therefore, be used both with character-based passwords by using an on-screen keyboard and with graphical password schemes as surveyed in. A variety of considerations is important for ensuring usability and security. Eye tracking technology has come a long way since its origins in the early 1900s. State of the art eye trackers offers non-encumbering, remote video-based eye tracking with an accuracy of 1˚ of visual angle. Eye trackers are a specialized application of computer vision. A camera is used to monitor the user’s eyes. One or more infrared light sources illuminate the user’s face and produce a glint – a reflection of the light source on the cornea. As the user looks in different directions the pupil moves but the location of the glint on the cornea remains fixed. The relative motion and position of the center of the pupil and the glint are used to estimate the gaze vector, which is then mapped to coordinates on the screen plane.
Painting album mechanism
Painting Album Mechanism is an anti-shoulder surfing mechanism, which has characteristics of both recall and recognition graphical techniques. Thus, this mechanism is also a hybrid graphical password anti-shoulder surfing mechanism. It was developed based on results of user’s affinity of choices, and through observation on the way kids are behave, while they paint the picture. When this mechanism was developed, results from user’s affinity of choice survey had become the mechanism’s architecture. Meantime, outcome of the observation have created this mechanism three input schemes, where we named it Swipe Scheme, Color Scheme, and Scot Scheme. In Painting Album Mechanism, Swipe Scheme, Color Scheme, and Scot Scheme are the methods for password creation. Each input scheme is non-identical, and it is user’s options to choose the input scheme they prefer
Text based graphical password schemes
To overcome the drawbacks of text-based authentication, researchers have been developed new password scheme which uses images, pictures as a password known as graphical password scheme. This scheme is used as an alternative to the alphanumeric password. Current authentication methods are categorized into three main areas: Token based authentication, Biometric based authentication, Knowledge-based authentication. In addition to this, a comparison of current graphical password techniques classified graphical password schemes into two categories viz. recognition-based and recall based approaches. Results answer the questions like “Is a graphical password as secure as a text-based password?” It also strives to find the answer to the question: “What are the major design and implementation issues for graphical passwords?” This study is useful in graphical password methods and wants to find the alternatives to overcome the susceptibility of it.
Secret tap method
Because of the important to take measures against covert observation in order to prevent authentication information from being stolen, Secret Tap method proposes a technique that do not expose the authentication information during entry, even if other individuals try to view the input process. Additionally, it should be noted that the risk of covert observation is not restricted to direct observation by other individuals, camera recordings also pose a threat. Therefore, it is necessary to make the authentication process more complex in order to prevent authentication information from being stolen even if cameras and/or other individuals observe the information input process numerous times. There are two types of shoulder-surfing attack: direct observation attacks, in which authentication information is obtained by a person who is directly monitoring the authentication sequence, and recording attacks, in which the authentication information is obtained by recording the authentication sequence for later analysis.
Secret Tap authentication method uses icons and a touch panel liquid crystal display. The goals and design policy used are,
Comparison of risks between alphanumeric and graphical Passwords
The primary benefit of graphical passwords compared to alphanumeric passwords is the improved memorability. However, the potential detriment of this advantage is the increased risk of shoulder-surfing. Graphical passwords that use graphics or pictures such as PassFaces, Jiminy, VIP, Passpoints or a combination of graphics and audio such as AVAP are likely all subject to this increased risk unless somehow mitigated in implementation. The results indicate the fact that both alphanumeric and graphical password-based authentication mechanisms may have a significant vulnerability to shoulder-surfing unless certain precautions are taken. Despite the common belief that nondictionary passwords are the most secure type of password-based authentication, our results demonstrate that it is, in fact, the most vulnerable configuration to shoulder-surfing.
PIN entry
Personal identification number is used to authenticate oneself in various situations, while withdrawing or depositing the money from automatic teller machine, unlock a phone, door, laptop or PDA. Though this method of authentication is a two step verification process in some situations, it is vulnerable to shoulder surfing attack. An attacker can obtain the PIN either by directly looking over the victim's shoulder or by recording the whole login process. So, various shoulder surfing resistant PIN entry methodologies are proposed to make the authentication process secure.
Cognitive trapdoor game
The cognitive trapdoor game has three groups involved in it: a machine verifier, a human prover, and a human observer. The goal of each group is, human prover has to input the PIN by answering the questions posed by the machine verifier while the observer tries to observe the interaction between the machine verifier and the human prover to know the PIN. A token is assigned to the prover as a unique identification by an authentic channel to prove his/her own identity. As the prover needs to authenticate themself in it is not easy for the observer to remember the whole login process unless the observer had a recording device. The cognitive trapdoor mechanism is resistant to direct shoulder surfing but not against the recording shoulder surfing.