swissentop mjkj       For best veiw use opera and you can cheakout our partner site for Photosop Learning: admin







Cellular System
Handover & Handoff
Gsm Channels
GSM Frequency
GSM Encrytion algorithmn







guest information


IP address:

host address:

browser info:
CCBot/2.0 (




    GSM Encryption Algorithmn



    A5/1 is a stream cipher used to provide over-the-air communication privacy in the GSM cellular telephone standard.

    A5/1 is used in Europe and the United States. A5/2 was a deliberate weakening of the algorithm for certain export regions.[1] A5/1 was developed in 1987, when GSM was not yet considered for use outside Europe, and A5/2 was developed in 1989. Though both were initially kept secret, the general design was leaked in 1994

    A GSM transmission is organised as sequences of bursts. In a typical channel and in one direction, one burst is sent every 4.615 milliseconds and contains 114 bits available for information. A5/1 is used to produce for each burst a 114 bit sequence of keystream which is XORed with the 114 bits prior to modulation. A5/1 is initialised using a 64-bit key together with a publicly-known 22-bit frame number.When operating in GPRS / EDGE mode, higher bandwidth radio modulation allows for larger 348 bits frames, and A5/3 is then used in a stream cipher mode to maintain confidentiality.


    Related Topics:

    0. Cellular System

    1. Handover(Handsoff),

    2. Inter BSS Intra MSCand Inter MSC call Handoff

    3. GSM Frequency

    4. Gsm Channels

    5. Call origination in GSM

    6. call Initiation in cellular

    7. GSM Encryption Algorithmn A5, A5/1, A5/2, A5/3

Visitor Counter
Visitor Counter