[dadalau],
The answer is 'not yet'. Currently the CLDC/MIDP 1.0 specification does not provide an SSL or equivalent implementation for the MIDP small devices yet. Hence CLDC/MIDP 1.0 does not provide any API for managing certificates and might be included in the next major release of the J2ME specification.
HTH.
Allen Lai
Developer Technical Support
SUN Microsystems
http://www.sun.com/developers/support/