<PAGE>                                                                       

Exhibit 4


AMENDMENT NO. 2
TO      
RIGHTS AGREEMENT


	This AMENDMENT NO. 2 TO RIGHTS AGREEMENT (the "Amendment") is entered into as 
of the 20th day of August, 1997 between Boston Technology, Inc., 
a Delaware corporation (the "Company"), and State Street Bank & Trust Company, 
a national banking association (the "Rights Agent").  Capitalized terms not 
otherwise defined herein shall have the meanings given them in the Rights 
Agreement by and between the parties hereto.


RECITALS

	WHEREAS, the Board of Directors has determined that it is in the best 
interests of the Company to amend the Rights Agreement as set forth herein 
prior to and in connection with the execution of that certain Agreement and 
Plan of Merger dated as of August 20, 1997, as the same may be amended from 
time to time (the "Merger Agreement"), between Comverse Technology, Inc., a 
New York corporation ("Comverse"), and the Company (pursuant to which Merger 
Agreement, among other things, the Company shall merge with and into Comverse 
(the "Merger")).

	WHEREAS, the Company has requested that the Rights Agreement be amended 
in accordance with Section 26 of the Rights Agreement, as set forth herein, and 
the Rights Agent is willing to amend the Rights Agreement as set forth herein.


AGREEMENT

	NOW, THEREFORE, the parties, intending to be legally bound, hereby 
agree as follows:

I. Section 7(a) of the Rights Agreement is hereby amended to read in its 
entirety as follows:

	"(a)  Subject to Section 7(e) hereof, the registered holder of any 
Rights Certificate may exercise the Rights evidenced thereby (except as 
otherwise provided herein including, without limitation, the restrictions on 
exercisability set forth in Section 9(c), Section 11(a)(iii) and Section 23(a) 
hereof) in whole or in part at any time after the Distribution Date upon 
surrender of the Rights Certificate, with the form of election to purchase 
and the certificate on the reverse side thereof duly executed, to the Rights 
Agent at the office of the Rights Agent designated for such purpose, together 
with payment of the aggregate Purchase Price with respect to the total number 
of shares of Common Stock (or other securities, cash or other assets, as the 
case may be) as to which such surrendered Rights are then exercisable, at or 
prior to the earlier of (i) the Final Expiration Date, (ii) the time at which 
the Rights are redeemed as provided in Section 23 hereof, or (iii) immediately 
prior to the Effective Time, as defined in the Agreement and Plan of Merger 
dated as of August 20, 1997, as the same may be amended from time to time, 
between Comverse Technology, Inc., a New York corporation ("Comverse"), and 
the Company (the "Merger Agreement"), pursuant to which Merger Agreement, among 
other things, the Company shall merge with and into Comverse (the "Merger") 
(the earlier of (i), (ii) and (iii) being herein referred to as the "Expiration 
Date")."

I. Section 34 of the Rights Agreement is hereby added as follows:

	"Section 34.  Comverse Transaction.  Notwithstanding any provision of 
this Rights Agreement to the contrary, no Distribution Date, Stock Acquisition 
Date or Triggering Event shall be deemed to have occurred, neither Comverse 
nor any Affiliate or Associate of Comverse shall be deemed to have become an 
Acquiring Person and no holder of Rights shall be entitled to exercise such 
Rights under or be entitled to any rights pursuant to Section 7(a), 11(a) or 
13(a) of this Rights Agreement by reason of (x) the approval, execution, 
delivery or effectiveness of the Merger Agreement or (y) the consummation of 
the transactions contemplated under the Merger Agreement in accordance with 
the terms thereof, (including, without limitation, the consummation of the 
Merger)."

I. Except as amended hereby, the Rights Agreement shall remain 
unchanged and shall remain in full force and effect.

I. This Amendment may be executed in any number of counterparts, each 
of which shall be an original, but all of which together shall constitute 
one instrument.

	IN WITNESS WHEREOF, the parties have caused this Amendment to be 
executed by their respective duly authorized representatives as of the date 
first above written.


					BOSTON TECHNOLOGY, INC. 


					By:     /s/   A. K. Wnorowski           
						--------------------------
						Name:  A. K. Wnorowski
						Title:  Senior Vice President 
						of Strategic Alliances
						and General Counsel


					STATE STREET BANK & TRUST COMPANY


					By:     /s/   Stephen Cesso             
						----------------------------
						Name:  Stephen Cesso
						Title:  Vice President 
						and Associate Counsel