After mounting a hostile bid for data encryption specialist Certicom, BlackBerry manufacturer Research In Motion has tabled an $18 million all-cash offer for Chalk Media and ‘pushcast’ software that delivers rich content to smartphones.

Chalk’s Mobile chalkboard product is used to push enterprise content out to employees or customers. Content can include large media assets like video or audio files, as well as surveys, or click to call and email requests.

Like a podcast file, the pushcast content sits on the device, so content pushed out is always available. To receive and track pushcasts, an on-board player needs to be installed which for a Blackberry or smartphone device is done over the air in less than a minute. 

Chalk’s board of directors has unanimously approved the acquisition and the Canadian-based companies expect the deal to close in February 2009.

This is one month after RIM’s tabled offer for the Certicom content security software house is due to expire. Certicom said on Thursday that it believes the $54 million approach “undervalues” its business.

It has since confirmed that it will be reviewing the offer, but also would be examining other strategic options.

That proposed acquisition is regarded as being highly tactical for RIM, as it would help accelerate take up of the Blackberry device by government and public sector authorities, which operate under strict security regimes.

Certicom provides the Elliptic Curve Cryptography public key system that has been adopted by the National Security Agency for government communications and provides the most security per bit of any known public key scheme.