This excerpt taken from the VRSN DEF 14A filed Apr 10, 2006.
A participant receiving restricted stock may be taxed in one of two ways: the participant (i) pays tax when the restrictions lapse (i.e., they become vested) or (ii) makes a special election to pay tax in the year the grant is made. At either time the value of the award for tax purposes is the excess of the fair market value of the shares at that time over the amount (if any) paid for the shares. This value is taxed as ordinary income and is subject to income tax withholding. VeriSign receives a tax deduction at the same time and for the same amount taxable to the participant. If a participant elects to be taxed at grant, then, when the restrictions lapse, there will be no further tax consequences attributable to the awarded stock until the recipient sells or otherwise disposes of the stock.