2. Why are there 2 SMS in my mobile’s Inbox when I receive an encrypted SMS
     message?

The IPCryptSIM uses the strongest commercially available encryption algorithm from RSA. Due to this the length of the SMS is extended and broken into 2 packets and sent as two SMS. However this offers an additional security feature, as the 2 packets can only be assembled on your mobile phone, thus if intercepted by an unauthorized third party it can not be opened. Our IPCryptSIM encryption conforms to the international security standards used by all international banks for their electronic banking and has been proven to be the maximum in security standards.

3. Why is encryption of SMS so important?

Encrypted SMS is becoming increasingly important as the examples of SMS intrusion, snooping, and interception multiply.

You probably heard the stories, and may have even read the published transcripts, of intercepted and incriminating mobile phone text messages sent between famous and notorious alike. Everyone loves Short Message Service (SMS). These small email-like notes are discreet, direct, and instantaneous; the required infrastructure has been well established. However the contents of SMS messages are known to the network operator's systems and personnel. Therefore, SMS, at a first glance would not offer an appropriate technology for secure communications. Most users do not realize how easy it may be to intercept.

Encrypting the text body of a SMS is the answer to safeguard confidential information from unauthorized access. SMS encryption is no longer new. However, until now SMS encryption has been developed for the up-market Java-based Smart Phones and PDAs only, leaving all simpler / cheaper GSM mobile phone users unprotected.

4. Why do I have to install the Public Key of the SMS Recipient?

Encryption is the process of transforming information so it is unintelligible to anyone but the intended recipient. Decryption is the process of transforming encrypted information so that it is intelligible again. A cryptographic algorithm, also called a cipher, is a mathematical function used for encryption or decryption. In most cases, two related functions are employed, one for encryption and the other for decryption.

With most modern cryptography, the ability to keep encrypted information secret is based not on the cryptographic algorithm, which is widely known, but on a number called a "key" that must be used with the algorithm to produce an encrypted result or to decrypt previously encrypted information. Decryption with the correct key is simple. Decryption without the correct key is impossible for all practical purposes.

Securely encrypting your SMS involves a pair of "keys", a Public Key and a Private Key. Data encrypted with your Public Key can be decrypted only with your Private Key. Whereas your Private Key is firmly embedded in the IPCryptSIM, your Public Key can be sent (we call this "exchanged", as you "swap" your Public Key with that of the other mobile phone) to other someone who has also a IPCryptSIM enabled mobile phone.

Not to worry, this is not difficult and is clearly explained in the User Manual you received with your IPCryptSIM. Once installed and the Public Keys are "exchanged" all you need to do is to write an SMS, select the recipient's mobile phone number from the Phone Book. IPCryptSIM takes care of the rest. The SMS will be encrypted and can ONLY be read (decrypted) by the recipient you had intended to send the SMS to.

5. How does the Public Key Exchange work?

When you install your IPCryptSIM into the SIM slot of your mobile device and you want to start the encryption functionality of your device you will have to "build" a user group and exchange your "Public key" with them. Obviously, each of the user group must have an IPCryptSIM installed as well.

To send your "Public Key" to another mobile device with an IPCryptSIM, you scroll through the menu to "IPCryptSIM", select is and chose "RSA Encryption".

Under this menu item scroll to "Configuration", select it and scroll to " Send Key" and press "OK".

If your IPCryptSIM is new you most likely do not have any mobile phone numbers in your phone book. Select "New Number", enter the mobile number of the desired mobile phone you want to send your Public key to and press "Send". The recipient will receive an encrypted SMS Message containing your Public Key.

Suppose you received this SMS Message with a Public Key in your mobile phones Message Inbox, scroll through your mobile device' Menu to "IPCryptSIM", select "RSA Encryption" and then scroll to "Phone Book". Under this menu item select "Add" and type into the respective space the name of the sender and press "OK". The senders mobile device number will be shown. If not, you can manually add the number. Press "OK" and the name, number and the Public Key of the sender will be saved automatically.

Now you are ready to send the first encrypted SMS message with this other person.

6. What happens when I install a Recipient’s Public Key?

Once the other mobile user has sent ("exchanged") the Public Key and you select "install" it will attach itself to the mobile phone number of the mobile phone it came from. In future, when you want to send an encrypted SMS message to this other mobile phone, by selecting the mobile phone number from the Phone Book the IPCryptSIM knows automatically which Public Key to use to encrypt the SMS message. This process is completely transparent to you and does not need any further interaction from you. We made the IPCryptSIM as user friendly as possible to make the sending of secure SMS messages pleasant and easy.

7. I have received the Public Key of another mobile phone, but there is no mobile phone
    number in my IPCryptSIM Phone Book.

When a Public Key is sent to your mobile device you first must install it. The IPCryptSIM will prompt you to do this. This requires that you manually add the name of the other mobile phone's owner and the mobile phone number. he key will automatically attach itself to the other mobile phone number when you press "install".

8. I have received an encrypted SMS, but I can’t decrypt and open it to see the clear
    text.

There might be 2 reasons why you can not open (decrypt) an encrypted SMS message you received.

You might not have received 2, but only 1 part of the 2-part SMS. This may be due to s network delay. Please wait for a few minutes and try again. If this problem persists and your mobile phone Messages Inbox shows 2 SMS, the message might have been interfered with and its content tampered with. This is a security measure of IPCryptSIM to warn you that there might have been an unauthorized tampering / interference of your encrypted SMS. In such a case better discard (cancel) the 2 encrypted SMS from your General Message Inbox and advice the sender to resend the encrypted SMS message.

9. What happens when I forget my PIN for IPCryptSIM?

The IPCryptSIM PIN is a 4-digit number, initially set at "1234". We strongly recommend that you change this PIN to one of your personal choice. If you forget your PIN, you will have a maximum of 3 tries before your IPCryptSIM in the mobile phone will be blocked. We therefore recommend that you note down, somewhere safe, the chosen PIN at the beginning when you initially change the PIN to your choice.

In the event you misplace this number and can not remember it, the best is to see your mobile operator, or your bank, whoever you received the IPCryptSIM from. They can reset the PIN.

According to our experience, a 4-digit PIN is easy to remember. Should your mobile phone be stolen or misused by an unauthorized person, he/she has only 3 tries to "figure out" your PIN before you mobile phone locks up to protect the data on your mobile device.

10. Why is the PIN of IPCryptSIM only 4 digits, while other PINs are more secure the
       more digit the PIN contains?

The IPCryptSIM uses a 4-digit PIN for user convenience. The PIN is completely secure as it is embedded in the SIM and not accessible by any person, not even the developers of the IPCryptSIM encryption application, nor anyone at the mobile telecom operator. In other application, as used by your PC for instance, the PIN is part of the application and is sent between the PC and the network. here it is recommended to have a longer and "more difficult" PIN for security reasons. Your mobile phone never sends the PIN with a SMS message. Your PIN always remains completely secure in the SIM of your mobile device, thus a 4-digit PIN is giving you as much security as any longer PIN. On top of this, if someone has gotten your mobile phone, whether maliciously or inadvertently, if this persons tries to find your PIN through tries, your mobile device will lock up after the 3rd wrong PIN entry and can no longer accessed without unblocking it. You received the IPCryptSIM PUK (a 8-digit unblocking number) with your IPCryptSIM. If your mobile phone has locked, you need to enter this PUK number to unblock it. Therefore, always keep this PUK safely stored away.

11. Can I use the IPCryptSIM when I change my SIM to another mobile phone?

Yes, IPCryptSIM works with all mobile devices that use a standard SIM. This way you can move your "encryption" from one mobile phone / device to another without having to purchase a new IPCryptSIM each time you want to acquire a newer mobile device.

All the settings you made initially, such as Public Key exchanges, etc. are stored on the IPCryptSIM and will immediately apply to any other mobile device you have moved the SIM to.

12. What is a “Private Key” and what is a "Public Key" and why is it called "key"?

To answer the last part first, the word "key" is used as it "unlocks" the encrypted SMS message. It's like a key used to access a safe place.

The RSA algorithm we use with IPCryptSIM is, what is called an "asymmetric" algorithm, made up of a "Private Key" that is securely embedded in the IPCryptSIM and can only be accessed by you using the PIN. It is used to decrypt SMS messages that have been encrypted with your "Public Key" the key you exchanged with other users that want to communicate through encrypted SMS messages with you.

In the context of electronic and mobile security, an asymmetric encryption algorithm, using a "Private Key" and a "Public Key" is the most secure way of encryption and is used by all major banks for e-banking and now also for m-banking.

13. Why do I receive 2 SMS even when the decrypted clear text is only 1 word?

To answer this might be a bit more technical than you expect. Computers process data as a "binary function", that is a language made up of "0" and "1"., being two numbers. To avoid that a user of a computer has to write binary functions to do some data processing, another "language" is used, called "hex decimal code" made up of numbers assigned to the letters, numbers, function keys and symbols of your computer key board. by typing, say the word "hello" on the key board the computer would receive this as the " hex decimal code" "104, 101, 108,108, 111", numbers which the computer then translates into the number strings made up of "0" and "1", as binary function. ("h", the first letter of "Hello"; which is "104" in "hex decimal code" is "1101000" as a binary function.

The SMS message you type on your mobile device is converted into a similar "0" and "1" function and the whole SMS message text body is just a large number string. When IPCryptSIM encrypts this number string it uses a mathematical formula, the RSA algorithm, and translate the number string into other numbers. These numbers, when you receive an encrypted SMS message make up the "garble" or illegible text. However, due to encryption the text body has been growing to 177 characters. Since a SMS message can only contain a maximum of 160 characters, the SMS is sent out as 2 SMS. Even, if you just send a SMS message with the word "hello" only, it will be sent as 2 SMS messages because every key board key has a number, including the "free space key".

As mentioned earlier, sending an encrypted SMS message in 2 parts adds further security because you can not open one part of the 2, only and decrypt. Your mobile device has to have both parts and "assemble" them to be able to decrypt the SMS message.

14. Can I forward a SMS to another mobile phone even though I received it encrypted?

Yes, but you must decrypt the message first and encrypt it with the Public Key of the intended recipient. Depending on the mobile phone model you might have to decrypt the SMS message and save it in your Messages folder first. However, we do not recommend that you use the "Forward" functionality. An encrypted SMS message is meant for your eye, only. It would be a better practice to write a new SMS and encrypt it for another recipient. This way you are in absolute control of the SMS message contents.

15. How many encrypted SMS can I store on my SIM?

This depends on the storage capacity of the SIM. IPCryptSIM usually is supplies as a 128kb SIM, that allows a maximum of 30 SMS to be stored. We recommend that you manage your encrypted SMS message, either through regularly "clearing" all older SMS message, or to move them to the mobile phone data store, should the mobile device you are using offer such a function.

16. Can I send an IPCryptSIM encrypted SMS message to a person in another country
        using a SIM of a different mobile operator?

Principally yes, as long as the other person in the other country has an IPCryptSIM. IPCryptSIM allows roaming anywhere in the world. If the SIM was issued with IPCryptSIM on board by the same mobile telecom operator and this persons travels abroad the standard roaming will apply.

However, as IPCS Group is rolling out IPCryptSIM in many other countries together with that countries' local mobile telecom operators, it is also possible to send encrypted SMS messages even if the mobile telecom operators are different.

Obviously, you must have done an exchange of the Public Keys beforehand!

17. Does IPCryptSIM work on any mobile device, such as mobile phones and PDAs?

IPCryptSIM works with all mobile devices that use a SIM, whether mobile phone, phone PDA, or any other mobile device. We developed our IPCryptSIM for the most widest use with almost all mobile devices, never mind their age. However, it is important to mention that devices several years old may have some device-dependent limitations, such as display and IPCryptSIM, although functioning perfectly well on such devices may show differences in its "normal" user-friendly appearance. solution for speech and data encryption on PDAs.