Implementation of A5/1 Stream Cipher

User 1

Enter The Message:

Output:

Key:

Frame:

User 2

Enter The Message:

Output:

About A5/1

A5/1 is a cipher developed in 1987 to protect the voice communication in mobile
networks according to the GSM standard. It is now regarded as broken. This is a simplified simulation of the cipher
This consists of the following steps:
1.Generate key from 64-bit key and 22 bit frame value
2.Encrypt The message from 1 user
3.Decrypt the message from other user
The key stream is linked to the plaintext (XOR) at the sender and thus the secret text is formed, which
can then be transmitted. The same key stream is formed at the receiver, which is
then linked to the secret text, in order to receive the clear text again.