<PAGE>   1
    As filed with the Securities and Exchange Commission on July 7, 1999
                                        Registration Statement No. 333-_________
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20552
                          -----------------------------

                        POST-EFFECTIVE AMENDMENT NO. 1 TO

                             REGISTRATION STATEMENT
                                   ON FORM S-4
                        UNDER THE SECURITIES ACT OF 1933

                                   ON FORM S-8
                          -----------------------------

                     SECURITY FIRST TECHNOLOGIES CORPORATION
             (Exact name of registrant as specified in its charter)

<TABLE>
<CAPTION>
<S>                                                                  <C>
                       Delaware                                               58-2395199
                       --------                                               ----------
(State or other jurisdiction of incorporation or organization)       (IRS Employer Identification No.)
</TABLE>

           3390 Peachtree Road, NE, Suite 1700, Atlanta, Georgia 30326
                    (Address of Principal Executive Offices)
                          -----------------------------

       SECURITY FIRST TECHNOLOGIES CORPORATION AMENDED AND RESTATED 1995
                              STOCK OPTION  PLAN
  SECURITY FIRST NETWORK BANK AMENDED AND RESTATED DIRECTORS' STOCK OPTION PLAN
     SECURITY FIRST NETWORK BANK STOCK OPTION AGREEMENT (ADVISORY DIRECTORS)
                   1995 STOCK OPTION PLAN OF SECUREWARE, INC.
         SECURITY FIRST NETWORK BANK STOCK OPTION AGREEMENT (SECUREWARE)
           SECURITY FIRST NETWORK BANK 1997 EMPLOYEE STOCK OPTION PLAN
    SECURITY FIRST TECHNOLOGIES CORPORATION 1998 DIRECTORS' STOCK OPTION PLAN
                    (Full title of the plans and agreements)
                            -------------------------

                               Robert F. Stockwell
                             Chief Financial Officer
                     Security First Technologies Corporation
                       3390 Peachtree Road, NE, Suite 1700
                             Atlanta, Georgia 30326
                     (Name and address of agent for service)

                                 (404) 812-6780
          (Telephone number, including area code of agent for service)

                                    COPY TO:

                              Stuart G. Stein, Esq.
                             Hogan & Hartson L.L.P.
                           555 Thirteenth Street, N.W.
                             Washington, D.C. 20004
                                 (202) 637-8575

                           --------------------------



                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
==============================================================================================================================
                                               AMOUNT        PROPOSED MAXIMUM      PROPOSED MAXIMUM            AMOUNT OF
                  TITLE OF SECURITIES           TO BE         OFFERING PRICE      AGGREGATE OFFERING          REGISTRATION
                    TO BE REGISTERED         REGISTERED         PER SHARE               PRICE                     FEE
---------------------------------------------------------------------------------------------------------- -------------------

<S>                                          <C>                    <C>              <C>                        <C>
Common Stock, par value $0.01 per share       12,491,862            $*               $161,835,125.06*           $44,990.16*
==============================================================================================================================
</TABLE>


(*)   Estimated solely for the purpose of calculating this fee pursuant to Rule
      457(c) and (h) under the Securities Act of 1933, as amended, based upon
      the weighted average exercise price of $16.92 for 966,818 shares and the
      average of the high and low prices for shares of common stock of Security
      First Technologies Corporation as reported on The Nasdaq Stock Market's
      National Market Tier of $39.50 for 3,682,951 shares calculated on the
      basis of June 29, 1999. The remaining 7,842,093 shares were registered
      under the Securities Act of 1933, as amended, as part of the 30,578,538
      (as adjusted to give effect to a 2-for-1 stock split in May 1999) shares
      registered pursuant to the registration statement on Form S-4 of Security
      First Technologies Corporation, as amended (File No. 333-56181) and are
      transferred to this Registration Statement.

================================================================================


<PAGE>   2




                                    FORM S-8
                             REGISTRATION STATEMENT


                                     PART I

                INFORMATION REQUIRED IN SECTION 10(a) PROSPECTUS

            The documents containing the information specified in Part I will be
sent or given to employees as specified by Rule 428(b)(1) under the Securities
Act of 1933. In accordance with the instructions to Part I of Form S-8 as
promulgated by the Securities and Exchange Commission, these documents will not
be filed with the SEC either as part of this registration statement or as
prospectuses or prospectus supplements pursuant to Rule 424 under the Securities
Act. These documents and the documents incorporated by reference into this
registration statement pursuant to Item 3 of Part II of this registration
statement, taken together, constitute the prospectus that meets the requirements
of Section 10(a) of the Securities Act.


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.              INCORPORATION OF DOCUMENTS BY REFERENCE.

            Security First Technologies Corporation, which we refer to as S1 or
the Registrant, hereby incorporates by reference into this registration
statement the following documents:

                     (a)    The Annual Report on Form 10-K of S1 for the fiscal
                            year ended December 31, 1998, as amended by S1's
                            Annual Report on Form 10-K/A for the fiscal year
                            ended December 31, 1998 filed with the SEC on May
                            14, 1999;

                     (b)    All other reports filed by S1 with the SEC pursuant
                            to Section 13(a) or 15(d) of the Securities Exchange
                            Act of 1934 since December 31, 1998; and

                     (c)    The description of S1's common stock, par value
                            $0.01 per share contained in S1's Registration
                            Statement on Form 8-A filed with the SEC on
                            September 30, 1998, including any amendment or
                            report filed for the purpose of updating such
                            description.

            In addition, all documents filed by S1 subsequent to the date hereof
pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act prior to
the filing of a post-effective amendment which indicates that all securities
offered have been sold or which deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference in this registration
statement and to be part of this registration statement from the date of filing
of such documents. Any statement contained in a document incorporated or deemed
to be incorporated by reference into this registration statement shall be deemed
to be modified or superseded for purposes of this registration statement to the
extent that a statement contained in this registration statement or in any other
subsequently filed document which also is or is deemed to be incorporated by
reference into this registration statement modifies or supersedes such
statement. Any such statement so modified or superseded shall not be deemed,
except as so modified or superseded, to constitute a part of this registration
statement.




<PAGE>   3


ITEM 4.                 DESCRIPTION OF SECURITIES.

            Not applicable.


ITEM 5.                 INTERESTS OF NAMED EXPERTS AND COUNSEL.

            Not applicable.


ITEM 6.                 INDEMNIFICATION OF DIRECTORS AND OFFICERS.

            Section 145 of the General Corporation Law of the State of Delaware
sets forth certain circumstances under which directors, officers, employees and
agents may be indemnified against liability that they may incur in their
capacity as such. Section 6 of S1's Amended and Restated Certificate of
Incorporation, as amended, provides for indemnification of S1's directors,
officers, employees and agents under certain circumstances. Section 6 of S1's
Amended and Restated Bylaws provides that S1 may purchase and maintain insurance
on behalf of directors, officers, employees or agents. S1 has in effect a policy
of liability insurance covering its directors and officers. Insofar as
indemnification for liabilities arising under the Securities Act may be
permitted to directors, officers and controlling persons of S1 pursuant to the
foregoing provisions, or otherwise, S1 has been advised that in the opinion of
the SEC such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by S1 of
expenses incurred or paid by a director, officer, or controlling person of S1 in
the successful defense of any action, suit, or proceeding) is asserted by such
director, officer, or controlling person in connection with the securities being
registered, S1 will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate jurisdiction
the question whether such indemnification by it is against public policy as
expressed in the Securities Act and will be governed by the final adjudication
of such issue.


ITEM 7.                 EXEMPTION FROM REGISTRATION CLAIMED.

            Not applicable.


ITEM 8.                 EXHIBITS.

<TABLE>
<CAPTION>
Exhibit
No.                          Description
---                          -----------

<S>         <C>
4.1         Amended and Restated Certificate of Incorporation of Security First
            Technologies Corporation ("S1") (filed as Exhibit 1 to S1's
            Registration Statement on Form 8-A filed with the Securities and
            Exchange Commission (the "SEC") on September 30, 1998 and
            incorporated herein by reference).

4.2         Certificate of Amendment of Amended and Restated Certificate of
            Incorporation of S1 (filed as Exhibit 4.2 to S1's Registration
            Statement on Form S-8 (File No. 333-82369) filed with the SEC on
            July 7, 1999 and incorporated herein by reference).

4.3         Certificate of Designation for S1's Series B Redeemable Convertible
            Preferred Stock (filed as Exhibit 2 to S1's Registration Statement
            on Form 8-A filed with the SEC on September 30, 1998 and
            incorporated herein by reference).
</TABLE>


<PAGE>   4

<TABLE>
<S>         <C>
4.4         Certificate of Designation for S1's Series C Redeemable Convertible
            Preferred Stock (filed as Exhibit 3 to S1's Quarterly Report on Form
            10-Q for the quarterly period ending March 31, 1999 and incorporated
            herein by reference).

4.5         Amended and Restated Bylaws of S1 (filed as Exhibit 3 to S1's
            Registration Statement on Form 8-A filed with the SEC on September
            30, 1998 and incorporated herein by reference).

4.6         Specimen certificate for S1's common stock (filed as Exhibit 4 to
            S1's Registration Statement on Form 8-A filed with the SEC on
            September 30, 1998 and incorporated herein by reference).

5           Opinion of Hogan & Hartson L.L.P. as to the legality of the
            securities registered hereunder, including the consent of that firm.

23.1        Consent of Hogan & Hartson L.L.P. (included as part of Exhibit 5).

23.2        Consent of KPMG LLP.

24          Power of Attorney.
</TABLE>



ITEM 9.     UNDERTAKINGS.

            (a)         The undersigned Registrant hereby undertakes:

                        (1)   To file, during any period in which offers or
                              sales are being made, a post-effective amendment
                              to this registration statement:

                              (i)       To include any prospectus required by
                                        section 10(a)(3) of the Securities Act;

                              (ii)      To reflect in the prospectus any facts
                                        or events arising after the effective
                                        date of the registration statement (or
                                        the most recent post-effective amendment
                                        thereof) which, individually or in the
                                        aggregate, represent a fundamental
                                        change in the information set forth in
                                        the registration statement; and

                              (iii)     To include any material information with
                                        respect to the plan of distribution not
                                        previously disclosed in the registration
                                        statement or any material change to such
                                        information in the registration
                                        statement.

                              (2)       That, for the purpose of determining any
                    liability under the Securities Act, each such post-effective
                    amendment shall be deemed to be a new registration statement
                    relating to the securities offered therein, and the offering
                    of such securities at that time shall be deemed to be the
                    initial bona fide offering thereof.

                               (3)      To remove from registration by means of
                    a post-effective amendment any of the securities being
                    registered which remain unsold at the termination of the
                    offering.
<PAGE>   5

            (b)         The undersigned Registrant hereby undertakes that, for
       purposes of determining any liability under the Securities Act, each
       filing of the Registrant's annual report pursuant to section 13(a) or
       section 15(d) of the Exchange Act (and, where applicable, each filing of
       an employee benefit plan's annual report pursuant to section 15(d) of the
       Exchange Act) that is incorporated by reference in the registration
       statement shall be deemed to be a new registration statement relating to
       the securities offered therein, and the offering of such securities at
       that time shall be deemed to be the initial bona fide offering thereof.

            (c)         The undertaking concerning indemnification is set forth
       under the response to Item 6.



<PAGE>   6



                                   SIGNATURES

            Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Atlanta, State of Georgia, on this 7th day of July,
1999.

                     SECURITY FIRST TECHNOLOGIES CORPORATION



                                   By:    /s/ ROBERT F. STOCKWELL
                                        ---------------------------------------
                                        Robert F. Stockwell
                                        Chief Financial Officer and Treasurer


            Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities indicated below on this 7th day of July, 1999.

<TABLE>
<CAPTION>
            SIGNATURE                                TITLE
            ---------                                -----
<S>                                                <C>

 /s/ JAMES S. MAHAN, III                             Chairman, Chief Executive Officer
-------------------------------                       and President
James S. Mahan, III                                  (Principal Executive Officer)


 /s/ ROBERT F. STOCKWELL                             Chief Financial Officer and
------------------------------                       Treasurer
Robert F. Stockwell                                  (Principal Financial Officer
                                                     and Principal Accounting
                                                     Officer)


 /s/ ROBERT W. COPELAN *                             Director
-----------------------------
Robert W. Copelan

 /s/ DORSEY R. GARDNER *                             Director
-----------------------------
Dorsey R. Gardner

                                                     Director
------------------------------
Joseph S. McCall

 /s/ HOWARD J. RUNNION, JR. *                        Director
-------------------------------
Howard J. Runnion, Jr.
</TABLE>

* By     /s/ ROBERT F. STOCKWELL
         --------------------------
         Robert F. Stockwell
         pursuant to Power of Attorney



<PAGE>   7



                                  EXHIBIT INDEX

<TABLE>
<CAPTION>
Exhibit
No.                             Description
---                             -----------
<S>         <C>
4.1         Amended and Restated Certificate of Incorporation of Security First
            Technologies Corporation ("S1") (filed as Exhibit 1 to S1's
            Registration Statement on Form 8-A filed with the Securities and
            Exchange Commission (the "SEC") on September 30, 1998 and
            incorporated herein by reference).

4.2         Certificate of Amendment of Amended and Restated Certificate of
            Incorporation of S1 (filed as Exhibit 4.2 to S1's Registration
            Statement on Form S-8 (File No. 333-82369) filed with the SEC on
            July 7, 1999 and incorporated herein by reference).

4.3         Certificate of Designation for S1's Series B Redeemable Convertible
            Preferred Stock (filed as Exhibit 2 to S1's Registration Statement
            on Form 8-A filed with the SEC on September 30, 1998 and
            incorporated herein by reference).

4.4         Certificate of Designation for S1's Series C Redeemable Convertible
            Preferred Stock (filed as Exhibit 3 to S1's Quarterly Report on Form
            10-Q for the quarterly period ending March 31, 1999 and incorporated
            herein by reference).

4.5         Amended and Restated Bylaws of S1 (filed as Exhibit 3 to S1's
            Registration Statement on Form 8-A filed with the SEC on September
            30, 1998 and incorporated herein by reference).

4.6         Specimen certificate for S1's common stock (filed as Exhibit 4 to
            S1's Registration Statement on Form 8-A filed with the SEC on
            September 30, 1998 and incorporated herein by reference).

5           Opinion of Hogan & Hartson L.L.P. as to the legality of the
            securities registered hereunder, including the consent of that firm.

23.1        Consent of Hogan & Hartson L.L.P. (included as part of Exhibit 5).

23.2        Consent of KPMG LLP.

24          Power of Attorney.
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 20301}]
{"company-data": {"conformed-name": "SECURITY FIRST TECHNOLOGIES CORP", "cik": "0001063254", "assigned-sic": "7370", "irs-number": "582395199", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-82381", "film-number": "99660009"}, "business-address": {"street1": "3390 PEACHTREE ROAD NE", "street2": "SUITE 1700", "city": "ATLANTA", "state": "GA", "zip": "30326", "phone": "4048126300"}, "mail-address": {"street1": "3390 PEACHTREE ROAD NE", "street2": "SUITE 1700", "city": "ATLANTA", "state": "GA", "zip": "30326"}}
1
    As filed with the Securities and Exchange Commission on July 7, 1999
                                        Registration Statement No. 333-_________
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20552
                          -----------------------------

                        POST-EFFECTIVE AMENDMENT NO. 1 TO

                             REGISTRATION STATEMENT
                                   ON FORM S-4
                        UNDER THE SECURITIES ACT OF 1933

                                   ON FORM S-8
                          -----------------------------

                     SECURITY FIRST TECHNOLOGIES CORPORATION
             (Exact name of registrant as specified in its charter)
Delaware                                               58-2395199
                       --------                                               ----------
(State or other jurisdiction of incorporation or organization)       (IRS Employer Identification No.)
3390 Peachtree Road, NE, Suite 1700, Atlanta, Georgia 30326
                    (Address of Principal Executive Offices)
                          -----------------------------

       SECURITY FIRST TECHNOLOGIES CORPORATION AMENDED AND RESTATED 1995
                              STOCK OPTION  PLAN
  SECURITY FIRST NETWORK BANK AMENDED AND RESTATED DIRECTORS' STOCK OPTION PLAN
     SECURITY FIRST NETWORK BANK STOCK OPTION AGREEMENT (ADVISORY DIRECTORS)
                   1995 STOCK OPTION PLAN OF SECUREWARE, INC.
         SECURITY FIRST NETWORK BANK STOCK OPTION AGREEMENT (SECUREWARE)
           SECURITY FIRST NETWORK BANK 1997 EMPLOYEE STOCK OPTION PLAN
    SECURITY FIRST TECHNOLOGIES CORPORATION 1998 DIRECTORS' STOCK OPTION PLAN
                    (Full title of the plans and agreements)
                            -------------------------

                               Robert F. Stockwell
                             Chief Financial Officer
                     Security First Technologies Corporation
                       3390 Peachtree Road, NE, Suite 1700
                             Atlanta, Georgia 30326
                     (Name and address of agent for service)

                                 (404) 812-6780
          (Telephone number, including area code of agent for service)

                                    COPY TO:

                              Stuart G. Stein, Esq.
                             Hogan & Hartson L.L.P.
                           555 Thirteenth Street, N.W.
                             Washington, D.C. 20004
                                 (202) 637-8575

                           --------------------------

                         CALCULATION OF REGISTRATION FEE
==============================================================================================================================
                                               AMOUNT        PROPOSED MAXIMUM      PROPOSED MAXIMUM            AMOUNT OF
                  TITLE OF SECURITIES           TO BE         OFFERING PRICE      AGGREGATE OFFERING          REGISTRATION
                    TO BE REGISTERED         REGISTERED         PER SHARE               PRICE                     FEE
---------------------------------------------------------------------------------------------------------- -------------------
Common Stock, par value $0.01 per share       12,491,862            $*               $161,835,125.06*           $44,990.16*
==============================================================================================================================
(*)   Estimated solely for the purpose of calculating this fee pursuant to Rule
      457(c) and (h) under the Securities Act of 1933, as amended, based upon
      the weighted average exercise price of $16.92 for 966,818 shares and the
      average of the high and low prices for shares of common stock of Security
      First Technologies Corporation as reported on The Nasdaq Stock Market's
      National Market Tier of $39.50 for 3,682,951 shares calculated on the
      basis of June 29, 1999. The remaining 7,842,093 shares were registered
      under the Securities Act of 1933, as amended, as part of the 30,578,538
      (as adjusted to give effect to a 2-for-1 stock split in May 1999) shares
      registered pursuant to the registration statement on Form S-4 of Security
      First Technologies Corporation, as amended (File No. 333-56181) and are
      transferred to this Registration Statement.

================================================================================
2

                                    FORM S-8
                             REGISTRATION STATEMENT

                                     PART I

                INFORMATION REQUIRED IN SECTION 10(a) PROSPECTUS

            The documents containing the information specified in Part I will be
sent or given to employees as specified by Rule 428(b)(1) under the Securities
Act of 1933. In accordance with the instructions to Part I of Form S-8 as
promulgated by the Securities and Exchange Commission, these documents will not
be filed with the SEC either as part of this registration statement or as
prospectuses or prospectus supplements pursuant to Rule 424 under the Securities
Act. These documents and the documents incorporated by reference into this
registration statement pursuant to Item 3 of Part II of this registration
statement, taken together, constitute the prospectus that meets the requirements
of Section 10(a) of the Securities Act.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.              INCORPORATION OF DOCUMENTS BY REFERENCE.

            Security First Technologies Corporation, which we refer to as S1 or
the Registrant, hereby incorporates by reference into this registration
statement the following documents:

                     (a)    The Annual Report on Form 10-K of S1 for the fiscal
                            year ended December 31, 1998, as amended by S1's
                            Annual Report on Form 10-K/A for the fiscal year
                            ended December 31, 1998 filed with the SEC on May
                            14, 1999;

                     (b)    All other reports filed by S1 with the SEC pursuant
                            to Section 13(a) or 15(d) of the Securities Exchange
                            Act of 1934 since December 31, 1998; and

                     (c)    The description of S1's common stock, par value
                            $0.01 per share contained in S1's Registration
                            Statement on Form 8-A filed with the SEC on
                            September 30, 1998, including any amendment or
                            report filed for the purpose of updating such
                            description.

            In addition, all documents filed by S1 subsequent to the date hereof
pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act prior to
the filing of a post-effective amendment which indicates that all securities
offered have been sold or which deregisters all securities then remaining
unsold, shall be deemed to be incorporated by reference in this registration
statement and to be part of this registration statement from the date of filing
of such documents. Any statement contained in a document incorporated or deemed
to be incorporated by reference into this registration statement shall be deemed
to be modified or superseded for purposes of this registration statement to the
extent that a statement contained in this registration statement or in any other
subsequently filed document which also is or is deemed to be incorporated by
reference into this registration statement modifies or supersedes such
statement. Any such statement so modified or superseded shall not be deemed,
except as so modified or superseded, to constitute a part of this registration
statement.
3

ITEM 4.                 DESCRIPTION OF SECURITIES.

            Not applicable.

ITEM 5.                 INTERESTS OF NAMED EXPERTS AND COUNSEL.

            Not applicable.

ITEM 6.                 INDEMNIFICATION OF DIRECTORS AND OFFICERS.

            Section 145 of the General Corporation Law of the State of Delaware
sets forth certain circumstances under which directors, officers, employees and
agents may be indemnified against liability that they may incur in their
capacity as such. Section 6 of S1's Amended and Restated Certificate of
Incorporation, as amended, provides for indemnification of S1's directors,
officers, employees and agents under certain circumstances. Section 6 of S1's
Amended and Restated Bylaws provides that S1 may purchase and maintain insurance
on behalf of directors, officers, employees or agents. S1 has in effect a policy
of liability insurance covering its directors and officers. Insofar as
indemnification for liabilities arising under the Securities Act may be
permitted to directors, officers and controlling persons of S1 pursuant to the
foregoing provisions, or otherwise, S1 has been advised that in the opinion of
the SEC such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by S1 of
expenses incurred or paid by a director, officer, or controlling person of S1 in
the successful defense of any action, suit, or proceeding) is asserted by such
director, officer, or controlling person in connection with the securities being
registered, S1 will, unless in the opinion of its counsel the matter has been
settled by controlling precedent, submit to a court of appropriate jurisdiction
the question whether such indemnification by it is against public policy as
expressed in the Securities Act and will be governed by the final adjudication
of such issue.

ITEM 7.                 EXEMPTION FROM REGISTRATION CLAIMED.

            Not applicable.

ITEM 8.                 EXHIBITS.
Exhibit
No.                          Description
---                          -----------
4.1         Amended and Restated Certificate of Incorporation of Security First
            Technologies Corporation ("S1") (filed as Exhibit 1 to S1's
            Registration Statement on Form 8-A filed with the Securities and
            Exchange Commission (the "SEC") on September 30, 1998 and
            incorporated herein by reference).

4.2         Certificate of Amendment of Amended and Restated Certificate of
            Incorporation of S1 (filed as Exhibit 4.2 to S1's Registration
            Statement on Form S-8 (File No. 333-82369) filed with the SEC on
            July 7, 1999 and incorporated herein by reference).

4.3         Certificate of Designation for S1's Series B Redeemable Convertible
            Preferred Stock (filed as Exhibit 2 to S1's Registration Statement
            on Form 8-A filed with the SEC on September 30, 1998 and
            incorporated herein by reference).
4
4.4         Certificate of Designation for S1's Series C Redeemable Convertible
            Preferred Stock (filed as Exhibit 3 to S1's Quarterly Report on Form
            10-Q for the quarterly period ending March 31, 1999 and incorporated
            herein by reference).

4.5         Amended and Restated Bylaws of S1 (filed as Exhibit 3 to S1's
            Registration Statement on Form 8-A filed with the SEC on September
            30, 1998 and incorporated herein by reference).

4.6         Specimen certificate for S1's common stock (filed as Exhibit 4 to
            S1's Registration Statement on Form 8-A filed with the SEC on
            September 30, 1998 and incorporated herein by reference).

5           Opinion of Hogan & Hartson L.L.P. as to the legality of the
            securities registered hereunder, including the consent of that firm.

23.1        Consent of Hogan & Hartson L.L.P. (included as part of Exhibit 5).

23.2        Consent of KPMG LLP.

24          Power of Attorney.
ITEM 9.     UNDERTAKINGS.

            (a)         The undersigned Registrant hereby undertakes:

                        (1)   To file, during any period in which offers or
                              sales are being made, a post-effective amendment
                              to this registration statement:

                              (i)       To include any prospectus required by
                                        section 10(a)(3) of the Securities Act;

                              (ii)      To reflect in the prospectus any facts
                                        or events arising after the effective
                                        date of the registration statement (or
                                        the most recent post-effective amendment
                                        thereof) which, individually or in the
                                        aggregate, represent a fundamental
                                        change in the information set forth in
                                        the registration statement; and

                              (iii)     To include any material information with
                                        respect to the plan of distribution not
                                        previously disclosed in the registration
                                        statement or any material change to such
                                        information in the registration
                                        statement.

                              (2)       That, for the purpose of determining any
                    liability under the Securities Act, each such post-effective
                    amendment shall be deemed to be a new registration statement
                    relating to the securities offered therein, and the offering
                    of such securities at that time shall be deemed to be the
                    initial bona fide offering thereof.

                               (3)      To remove from registration by means of
                    a post-effective amendment any of the securities being
                    registered which remain unsold at the termination of the
                    offering.
5

            (b)         The undersigned Registrant hereby undertakes that, for
       purposes of determining any liability under the Securities Act, each
       filing of the Registrant's annual report pursuant to section 13(a) or
       section 15(d) of the Exchange Act (and, where applicable, each filing of
       an employee benefit plan's annual report pursuant to section 15(d) of the
       Exchange Act) that is incorporated by reference in the registration
       statement shall be deemed to be a new registration statement relating to
       the securities offered therein, and the offering of such securities at
       that time shall be deemed to be the initial bona fide offering thereof.

            (c)         The undertaking concerning indemnification is set forth
       under the response to Item 6.
6

                                   SIGNATURES

            Pursuant to the requirements of the Securities Act of 1933, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Atlanta, State of Georgia, on this 7th day of July,
1999.

                     SECURITY FIRST TECHNOLOGIES CORPORATION

                                   By:    /s/ ROBERT F. STOCKWELL
                                        ---------------------------------------
                                        Robert F. Stockwell
                                        Chief Financial Officer and Treasurer

            Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities indicated below on this 7th day of July, 1999.
SIGNATURE                                TITLE
            ---------                                -----
/s/ JAMES S. MAHAN, III                             Chairman, Chief Executive Officer
-------------------------------                       and President
James S. Mahan, III                                  (Principal Executive Officer)

 /s/ ROBERT F. STOCKWELL                             Chief Financial Officer and
------------------------------                       Treasurer
Robert F. Stockwell                                  (Principal Financial Officer
                                                     and Principal Accounting
                                                     Officer)

 /s/ ROBERT W. COPELAN *                             Director
-----------------------------
Robert W. Copelan

 /s/ DORSEY R. GARDNER *                             Director
-----------------------------
Dorsey R. Gardner

                                                     Director
------------------------------
Joseph S. McCall

 /s/ HOWARD J. RUNNION, JR. *                        Director
-------------------------------
Howard J. Runnion, Jr.
* By     /s/ ROBERT F. STOCKWELL
         --------------------------
         Robert F. Stockwell
         pursuant to Power of Attorney
7

                                  EXHIBIT INDEX
Exhibit
No.                             Description
---                             -----------
4.1         Amended and Restated Certificate of Incorporation of Security First
            Technologies Corporation ("S1") (filed as Exhibit 1 to S1's
            Registration Statement on Form 8-A filed with the Securities and
            Exchange Commission (the "SEC") on September 30, 1998 and
            incorporated herein by reference).

4.2         Certificate of Amendment of Amended and Restated Certificate of
            Incorporation of S1 (filed as Exhibit 4.2 to S1's Registration
            Statement on Form S-8 (File No. 333-82369) filed with the SEC on
            July 7, 1999 and incorporated herein by reference).

4.3         Certificate of Designation for S1's Series B Redeemable Convertible
            Preferred Stock (filed as Exhibit 2 to S1's Registration Statement
            on Form 8-A filed with the SEC on September 30, 1998 and
            incorporated herein by reference).

4.4         Certificate of Designation for S1's Series C Redeemable Convertible
            Preferred Stock (filed as Exhibit 3 to S1's Quarterly Report on Form
            10-Q for the quarterly period ending March 31, 1999 and incorporated
            herein by reference).

4.5         Amended and Restated Bylaws of S1 (filed as Exhibit 3 to S1's
            Registration Statement on Form 8-A filed with the SEC on September
            30, 1998 and incorporated herein by reference).

4.6         Specimen certificate for S1's common stock (filed as Exhibit 4 to
            S1's Registration Statement on Form 8-A filed with the SEC on
            September 30, 1998 and incorporated herein by reference).

5           Opinion of Hogan & Hartson L.L.P. as to the legality of the
            securities registered hereunder, including the consent of that firm.

23.1        Consent of Hogan & Hartson L.L.P. (included as part of Exhibit 5).

23.2        Consent of KPMG LLP.

24          Power of Attorney.