New Delhi, Aug 12 (PTI): Stepping up the pressure on BlackBerry mobile phone services, government today asked the phone-makers Research In Motion as well as telecom operators to provide a technical solution by August 31 or face ban.

In a letter to to the Department of Telecom Secretary P J Thomas, Union Home Secretary G K Pillai asked him to convey to the operators and Canada-based RIM that a technical solution to make available lawful interception of BlackBerry Enterprise Services (BES) and BlackBerry Messenger Services (BBM) by August 31 or its services will be blocked.

The letter was sent after a meeting chaired by Pillai in which representatives of security agencies, Telecom Department and top brass of state-owned BSNL and MTNL were present.

According to a Union Home Ministry spokesman, "the meeting today asked DoT to convey to service providers and RIM that the BES and messanger services be made accessible to Legal Enforcement Agencies (LEA) and find a technical solution by August 31.

"If a technical solution is not found by August 31, government will review the position and take steps to block these two services. As of now voicemail, SMS and Blackberry Internet Services (BIS) have been made available to the LEA," the spokesman said.

Today's discussion was aimed at finalising the government strategy towards BlackBerry phone which is facing the threat of being blocked in the country if telecom service providers do not address government's security concerns.

Ahead of the meeting, a top official of RIM, which has nearly one million subscribers in the country and has a growing market, made a courtsey call on Home Minister P Chidambaram.

Last week, BlackBerry had made a fresh attempt to break the logjam over its services in India by offering "metadata" and relevant information to security agencies which will enable them to lawfully intercept communication on such phones but it failed to enthuse them.

RIM representatives explained that BlackBerry mobile device sends encrypted emails, which is sent to BlackBerry Enterprise Server (BES) located with the service provider.

BES decrypts messages and sends it to the email server of the service provider where it remains stored in decrypted form. Then it is pushed to the BlackBerry device in encrypted. UAE had recently banned Blackberry services.