A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are not in the same vicinity of each other to be heard directly.

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60
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7answers
17k views

How hard is it to intercept SMS (two-factor authentication)?

A lot of two-factor authentication mechanisms use SMS to deliver single-use passphrase to the user. So how secure is it? Is it hard to intercept the SMS message containing the passphrase? Do mobile ...
51
votes
5answers
10k views

Is sending passwords through cellphone text messages secure?

Both the sender and the receiver deleted the text after it was sent, but is it still possible that it exists somewhere and that someone can get to it?
48
votes
11answers
17k views

If someone asks to borrow your phone to make a call, what could they do?

A stranger walks up to you on the street. They say they lost their phone and need to make a phone call (has happened to me twice, and maybe to you). What's the worst a phone call could do? Let's ...
39
votes
5answers
6k views

Bring your own phone to a (new) job: Consequences?

I am starting a new job, and I have the choice to receive a phone from the company, or bring my own phone. I am considering using my own phone, to avoid having an extra device, but I want to better ...
34
votes
5answers
54k views

How to trace a (mobile) phone?

Even since growing up, I've watched films in which the "bad guy" is repeatedly tracked down when they call the police or FBI or police force de jour. They always have "about 30 seconds". Regardless ...
33
votes
5answers
18k views

What is preventing us from sniffing the mobile phone communication?

I'm learning wireless penetration testing. It really is amazing. But it made me wonder, what about mobile phones? They are also means of wireless communication. So, our entire voice must be in the air ...
27
votes
3answers
5k views

Why do I need to hide my phone's IMEI

If it is a secret then why is it visible on the box, invoice and the back of the phone? If it is not a secret then why does it have to be blurred when it gets posted online?
25
votes
4answers
14k views

Can A Powered Down Cell Phone be Turned On Remotely?

I know this is tin-foil hat fodder, but at least one judicial opinion (http://www.politechbot.com/docs/fbi.ardito.roving.bug.opinion.120106.txt) referenced a bug that could track/listen in on the ...
25
votes
9answers
10k views

Do secure phone lines exist?

I could be out of context here about security, but , I would like to know if phone lines or phone calls over VOIP could be made secure . I know that Skype and other VOIP service providers have to ...
22
votes
4answers
10k views

Are phone calls on a GSM network encrypted?

When I make a call on my cellphone (on a GSM network), is it encrypted?
22
votes
2answers
2k views

Security implications of rooting Android

My Android smart phone has fancy features that I can get only if I root it, e.g., free-wifi tethering or Cisco VPN (with group name/password). However, the procedure to root my phone makes me ...
19
votes
3answers
2k views

Could my bank's two-factor authentication be hacked?

When I attempt to log in to my bank, an SMS code is sent to my phone. I then type this nine-character code into the bank's Web site, to login to my account. Is this vulnerable to attack, without ...
18
votes
2answers
52k views

Can Android phone running without SIM card be tracked (localized) by police?

I am running an Android phone without a SIM card. I am using it for web surfing. Can the police localize my phone using the cell towers (BTS)? In other words, I know Android phones emit radiations ...
18
votes
1answer
8k views

How can I spoof a phone call and make it appear to come from another phone?

I'm performing a penetration test against a company. Part of my social engineering procedure is to contact the IT department and try to convince them to that I'm an employee in the company and get ...
17
votes
3answers
990 views

Someone faxed me a bunch of black paper

I work for this telemarketing company, and when I went to work this morning all my fax machines' outputs were jammed with black paper with the faded words "fuck you" transcribed on each of them. I ...
17
votes
3answers
2k views

Is my phone carrier monitoring my traffic?

Today I started using a VPN on my phone (nexus 5), and after I switched on mobile data and turned off my WiFi, I received a text message from my carrier offering me roaming packages for Europe (which ...
15
votes
4answers
840 views

Does two-factor authentication reduce the need for a long password?

I've recently enabled 2-factor auth on a number of web apps, mostly using Google Authenticator. Does this mean that the importance of a strong password on each site is reduced? I would prefer to use ...
14
votes
2answers
49k views

Is it possible to make a phone call appear to come from another phone, even to the network provider?

Quick Question Is it possible that I could call a mobile number, but have the call forwarded through another number active on a different phone that someone else has? I have had unlimited access to ...
14
votes
3answers
483 views

Android security without updates

I have an android phone which, like many others, has quickly become unsupported and is not receiving any updates. At the same time there are publicly available exploits for privilege-escalation ...
12
votes
2answers
1k views

Should I change phone number and e-mail address after PayPal fraud?

I have been the victim of PayPal fraud. I hadn't used PayPal in a year and then within 9 days there were three unauthorized transactions on my account for a total of 150 Canadian dollars and 290 ...
12
votes
2answers
1k views

Protecting cellphones from USB attacks (a.k.a. Juice Jacking)

We have several smartphone with encrypted data on them (BES, iPhone, Android) and want to prevent an unauthorized person from downloading information from the device via USB. The visual assumption ...
10
votes
1answer
27k views

How to spoof a cell phone tower (cell site, base station) — homemade IMSI-Catcher

An answer to a recent question has given me an idea for a school project (security CS program). Also, an active attacker (with a fake base station) can potentially force a mobile phone to use ...
9
votes
2answers
2k views

Phone calls that listen to you saying hello and then say “goodbye” [closed]

I live in France. About 5-10 times, once every 1-2 months, I receive an automated computerized call that listens to me say "hello" there is silence for 5 seconds, and then there is a voice recording ...
9
votes
3answers
553 views

Is secure Caller ID possible for SIP / VOIP?

Is there any way (standard, proposed or draft) that will allow for secure Caller ID over SIP / VOIP networks? I have constantly heard that Caller ID is insecure when used over these services. Can ...
9
votes
2answers
2k views

How do I protect my Gmail account when accessing it via an Android smartphone?

I have a Gmail account that I also access via an Android smartphone. The mail account could be used to reset passwords for other online accounts, so I want to tighten up the security around this ...
7
votes
4answers
578 views

airgap a smartphone?

im looking to use my smartphone purely as a portable computer, with no network functionality in order to protect my privacy, is removing the sim cards from it enough to airgap it or do i need to go ...
7
votes
2answers
1k views

How do I forensically determine whether a mobile phone has been infected with a spy suite?

What is the best way of forensically determining that spyware software has been installed on the phones without making any changes to the phone(s)? I have Blackberry and iPhone 4 phones that are ...
7
votes
5answers
3k views

How should I safely display my phone number on my Website?

If I display my email address on my Website, I would probably receive a lot of Spam, so I can set up a contact form instead. If I want to display my phone number, how can I prevent unwanted phone ...
6
votes
3answers
2k views

Do cell-phones exist with open source baseband processors?

In a recent question (can't seem to find now), someone asked: Is it possible to track a phone which is off? and received a response of Who's to say that it's really off? Your phone has both ...
6
votes
4answers
335 views

Why do phones have SIM cards? [closed]

I presume that the main reason phone operators require a SIM card to get access to the network is due to security and/or authentication purposes. Just wondering why this is? What does a SIM card do ...
6
votes
3answers
5k views

What makes the Blackberry device and network more secure?

One of Blackberry's strongest assets is the "network" that it uses. Can someone explain, or link to technical information that covers what this secure network is, and what it does better than the ...
6
votes
2answers
340 views

Can a SMS recipient charge any arbitrary fee to the sender without approval?

I received an email from a prospective "client" in broken English. We have been going back and forth about services for a while and he wants me to text him. Is it possible for him to charge me some ...
6
votes
2answers
11k views

Is it possible to crack a PIN / PUK code on a phone SIM card?

When deploying a mobile phone best practices policy, one of the points which were raised was the requirement for the user to protect his SIM card with a PIN. The theory is that three failed attempts ...
6
votes
3answers
309 views

Is Twitter digits login (sms auth code) insecure?

Twitter released(some time ago) a new kit named Digits which allows the client to login with a phone number and an authorization code (received through sms). I find it great for the user experience ...
6
votes
2answers
781 views

How can I protect my phone voicemail from being hacked?

With the News of The World Phone Hacking scandal spreading globally amidst allegations that as well as celebrities, victims of September 11 and other major events in the news have had their phone ...
5
votes
5answers
4k views

Is it possible for a phone to be transmitting even while turned off and the battery removed?

Is it technically or theoretically possible for any part of a mobile phone's circuitry to be still on and transmitting even while turned off and the battery has been removed? If so, how? I am ...
5
votes
3answers
354 views

Mutual authentication for humans

Is there any way for two people to securely authenticate each other without access to any special software (like PGP)? For example, when speaking over the phone or by sending SMSes to each other or ...
5
votes
2answers
572 views

Mobile phone security eavesdropping based on data transfer

is there an easy way for particular governmental organizations (especially in countries where freedom of speech is a problem) have some technology where they can easily eavesdrop on cellphone internet ...
5
votes
2answers
456 views

How are “fake cell towers” detected

With the recent (and not so recent) news about fake cell towers popping up in different part of the world, I was wondering how these are detected (from a technical point of view). I'm not really ...
5
votes
3answers
2k views

Which is safer, GSM or CDMA?

I have read in the past (no sure where) that unfortunately there exist illegal devices that permit crooks to eavesdrop on GSM mobile phone conversations. I recently also heard that some people had ...
5
votes
1answer
135 views

Symbiote Counter-Attack Detection

I saw this video on YouTube about hacking Cisco phones (and other embedded systems) and I was overjoyed when the presenter not only hacked, but presented a security solution. Intrigued, I started ...
5
votes
2answers
596 views

Has there been any documented cases where hackers have hijacked the phone number to a business?

Has there been any cases where hackers have taken over the phone number to a business, by creating a phone number in the same area code, setting up a virtual PBX / Asterisk system, routing all calls ...
5
votes
1answer
647 views

Trying to prevent Cisco toll fraud

A little back story on the setup first; We have a Cisco VoIP setup at our remote office(where I'm at) and the main CCM/CCX/Unity setup is at the parent company across the US in Connecticut. We have ...
4
votes
2answers
510 views

Cell phone voice mail hacking

The news has been filled recently with the allegations that News of the World employees hacked into the voicemail inboxes of celebrities and crime victims. What flaw was exploited to accomplish this, ...
4
votes
2answers
194 views

Sensitive data and phone calls

How safe is it to give sensitive information to someone over a phone line? Does it matter if the data was verbally spoken or if it was typed in? Example: Opening an account with an internet provider ...
4
votes
1answer
138 views

Voice Call Safety

When i was dealing with an assistant of my bank through mobile call, she asked me to insert my bank login code after a beep. I was wondering if this procedure is secure against a malicious agent who ...
4
votes
1answer
13k views

How to track a Spoofed SMS on Iphone

A mate pulled a quality prank on me the other day by sending me a SMS via a Spoofed number. He's bought a SMS gateway and can set the message ID/phone number to be 'God' (or whatever he wants(letters ...
4
votes
2answers
196 views

Options for simple phone verification with pin delivery

My website needs to verify phone numbers in order to ensure that customers claiming a business actually work there. The service calls and gives the customer a pin which they put into the site. Many ...
4
votes
2answers
983 views

Does a TMSI change often enough to prevent tracking?

A company called Path Intelligence has a product called Footpath which uses the TMSI, WiFi MAC address, and bluetooth MAC address to track phones as they move through stores. However, I don't see ...
4
votes
0answers
74 views

Deal with number changes in a phone number based authentication/login system

Twitter Digits (https://get.fabric.io/digits) provides an authentication/login system based on phone numbers for mobile apps, and several other mobile apps (e.g. Square Cash, ...