A German boffin has cracked and published the secret code used to encrypt most of the world’s digital mobile phone calls.

Karsten Nohl said that he had published the GSM algorithm to show how ineffective the 21-year-old GSM code was today. The code was developed in 1988 and still used to protect the privacy of 80 percent of mobile calls worldwide.

Nohl said that the it shows that the existing GSM security is inadequate. He wants operators to adopt better security measures for mobile phone calls.The GSM Association dubbed Nohl’s efforts illegal and said they overstated the security threat to wireless calls.

Analysts say that the industry now has about six months to sort out GSM security before some bright spack comes up with a decent exploit.