A-Key Calculator - Version 1.0 This program is a useful tool for cellular phone industry, TDMA and CDMA network engineers and security managers, as well as everyone who is involved in developing and testing the TDMA and CDMA handsets with the built-in authentication function based on the CAVE algorithm as defined in IS-54 (Appendix A), TSB50, TSB51, IS-95, IS-136 and TIA-627 standards.Now everyone can create a valid authentication key (A-Key), 0 to 20 digits long, with an accompanying 6 digit cheksum calculated for any given ESN number. The generated sequence of digits can be entered from the phone's keypad to reprogram the phone's A-Key for testing purposes or mobile phone activation. After entering those digits the phone must display "VALID". This means that the new A-Key value is accepted. Otherwise the phone will display "INVALID" which means that either the last 6 digits of A-Key are not correct or there is a problem with the phone. With this program you can also validate an existing A-Key for any particular ESN number. The ESN can be entered in decimal or hexadecimal format, you can convert it from one format to another. A useful option is resolving the ESN prefix and determining the legitimate phone's manufacturer. After you have entered enough digits of the ESN the legitimate manufacturer name will be displayed automatically.