LIMITED POWER OF ATTORNEY

The undersigned hereby constitutes and appoints each of Tram Phi, Mary Keller,
and Shulamite White signing singly, and with full power of substitution,
the undersigned's true and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's capacity
as an officer and/or director of Imperva, Inc. (the "Company"), from time to
time the following U.S. Securities and Exchange Commission ("SEC") forms: (i)
Form ID, including any attached documents, to effect the assignment of codes to
the undersigned to be used in the transmission of information to the SEC using
the EDGAR System; (ii) Form 3, Initial Statement of Beneficial Ownership of
Securities, including any attached documents; (iii) Form 4, Statement of Changes
in Beneficial Ownership of Securities, including any attached documents; (iv)
Form 5, Annual Statement of Beneficial Ownership of Securities in accordance
with Section 16(a) of the Securities Exchange Act of 1934, as amended, and the
rules thereunder, including any attached documents; (v) Schedule 13D; and (vi)
amendments of each thereof, in accordance with the Securities Exchange Act of
1934, as amended, and the rules thereunder, including any attached documents;

(2) do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form 3, 4 or 5,
Schedule 13D or any amendment(s) thereto, and timely file such form(s) with the
SEC and any securities exchange, national association or similar authority;

(3) seek or obtain, as the undersigned's representative and on the undersigned's
behalf, information regarding transactions in the Company's securities from any
third party, including brokers, employee benefit plan administrators and
trustees, and the undersigned hereby authorizes any such person to release any
such information to each of the undersigned's attorneys-in-fact appointed by
this Power of Attorney and approves and ratifies any such release of
information; and

(4) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact, acting singly, full
power and authority to do and perform any and every act and thing whatsoever
requisite, necessary or proper to be done in the exercise of any of the rights
and powers herein granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with full power of
substitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorney-in-fact's substitute or substitutes, shall
lawfully do or cause to be done by virtue of this power of attorney and the
rights and powers herein granted.

The undersigned acknowledges that:

(1) the foregoing attorneys-in-fact, in serving in such capacity at the request
of the undersigned, are not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 or Regulation 13D-G of
the Securities Exchange Act of 1934, as amended, including without limitation
(a) any liability of the undersigned for any failure to comply with such
requirements, or (b) any obligation or liability of the undersigned for profit
disgorgement under Section 16(b) of the Securities Exchange Act of 1934, as
amended, and this Power of Attorney does not relieve the undersigned from
responsibility for compliance with any such responsibilities, obligations or
liabilities;

(2) this Power of Attorney authorizes, but does not require, each such
attorney-in-fact to act in his or her discretion on information provided to such
attorney-in-fact without independent verification of such information; and

(3) any documents prepared and/or executed by any such attorney-in-fact on
behalf of the undersigned pursuant to this Power of Attorney will be in such
form and will contain such information and disclosure as such attorney-in-fact,
in his or her discretion, deems necessary or desirable.

The undersigned hereby agrees to indemnify each attorney-in-fact and the Company
from and against any demand, damage, loss, cost or expense arising from any
false or misleading information provided by the undersigned to the attorney-in
fact.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file such forms with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of February 2, 2016.

               /s/ Terrence J. Schmid
                   Terrence J. Schmid