encrypt a string in midlet

[nickyeng]

i have a midlet which will generate a string (message ) and send to our gateway.

but before sending, i will need to encrypt the string.

i've checked anywhere in internet but couldn't find j2me API about encryption.

what is the simple way to encrypt that string in midlet ?

anyone idea?

from
Nick

[JosAH]

What decryption method is used on the other side of the wire?

kind regards,

Jos

[nickyeng]

What decryption method is used on the other side of the wire?

kind regards,

Jos

you mean gateway side ?

of course decryption method will be the compatible with encryption method in midlet side. Means will use same package for encryption and decryption methods.

is it necessary for developer to encrypt the message that is sending out in midlet internally ?

Without encryption, the message from midlet SMS out to our gateway ( sms://+12345 ), for example a string message "REGISTER 1234"...will it be intercepted by other people WHEN the time the message is on the way to gateway.... ?

[JosAH]

you mean gateway side ?

of course decryption method will be the compatible with encryption method in midlet side. Means will use same package for encryption and decryption methods.

is it necessary for developer to encrypt the message that is sending out in midlet internally ?

Without encryption, the message from midlet SMS out to our gateway ( sms://+12345 ), for example a string message "REGISTER 1234"...will it be intercepted by other people WHEN the time the message is on the way to gateway.... ?

Ah, ok; so the en/decryption methods are up to you? I don't know your configuration
but I'd say that nothing *un*crypted should exist starting from your DMZ to the
outside world. Internally things can just pass uncrypted from one peer to another.

About the en/decryption itself: how much processing power have you available?

kind regards,

Jos

[nickyeng]

Ah, ok; so the en/decryption methods are up to you? I don't know your configuration
but I'd say that nothing *un*crypted should exist starting from your DMZ to the
outside world. Internally things can just pass uncrypted from one peer to another.

About the en/decryption itself: how much processing power have you available?

kind regards,

Jos

what do you mean by processing power ?

our midlet should be the smallest size like 300kb....
today, my supervisor do not like Bouncy Castle encryption/decryption OR JSR177 because importing those jar files willl make midlet size increases.

i'm not so good in packaging jar for midlet, Do i need to put Bouncy Castle jar files into the jar file that creates midlet (the jar for us to install midlet in phone--i use usb cable to put jar into phone and then install from phone) ?

cos i have a folder which holds alot of jar files that midlet needs under my application directory e.g. /MyApp/j2melib/
so when i hit the "Create Package" option from droplist, it creates one jar file and one jad file under /MyApp/deployed/ directory. /deployed/ directory is automatic created once hit the option.

my supervisor want me to copy "formula" and use it to create my own classes to have encryption function. I am so confused by what he meant "formula".

I have no idea about creating my own encrypt function. And even if i use Bouncy Castle package, console shows me Warning message.

what can i do now?
i'm stuck with this for 2 days already...
i am so fresh =.=

from noob
Nick

[JosAH]

what do you mean by processing power ?

our midlet should be the smallest size like 300kb....

Just as I wrote: "processing power" as in "how fast is your processor and how
much memory can you spare for the encryption process". As you described
your phone is quite small and I guess it's quite slow as well so a feasible and
valid option could be to implement a cheap and fast home brew encryption and
decryption algorithm.

How secure should your encryption method be? Can there be any communication
between the phone and the other side before the encrypted data is sent?

kind regards,

Jos

[nickyeng]

Just as I wrote: "processing power" as in "how fast is your processor and how
much memory can you spare for the encryption process". As you described
your phone is quite small and I guess it's quite slow as well so a feasible and
valid option could be to implement a cheap and fast home brew encryption and
decryption algorithm.

How secure should your encryption method be? Can there be any communication
between the phone and the other side before the encrypted data is sent?

kind regards,

Jos

no communication with other side before the encryption.

Actually i just want a very small simple encryption function. You ask me like it is a very big process. hehe.

encrypt a string in phone and then send out(sms out) ... that's it.

thanks
from
Nick