SUBSIDIARY GUARANTEE

FOR VALUE RECEIVED, and in consideration of note purchases from, or credit otherwise extended or to be extended by Laurus Master Fund, Ltd. (“Laurus”) to or for the account of Implant Sciences Corporation, a Massachusetts corporation (the “Parent”) and each of C Acquisition Corporation, a Delaware corporation (d/b/a Core Systems) and Accurel Systems International Corporation, a California Corporation (together with the Parent, the “Companies” and each, a “Company”) from time to time and at any time and for other good and valuable consideration and to induce Laurus, in its discretion, to purchase such notes or make other extensions of credit and to make or grant such renewals, extensions, releases of collateral or relinquishments of legal rights as Laurus may deem advisable, each of the undersigned (and each of them if more than one, the liability under this Guaranty being joint and several) (jointly and severally referred to as “Guarantors” or “the undersigned”) unconditionally guaranties to Laurus, its successors, endorsees and assigns the prompt payment when due (whether by acceleration or otherwise) of all present and future obligations and liabilities of any and all kinds of each Company to Laurus and of all instruments of any nature evidencing or relating to any such obligations and liabilities upon which such Company or one or more parties and such Company is or may become liable to Laurus, whether incurred by such Company as maker, endorser, drawer, acceptor, guarantors, accommodation party or otherwise, and whether due or to become due, secured or unsecured, absolute or contingent, joint or several, and however or whenever acquired by Laurus, whether arising under, out of, or in connection with (i) that certain Securities Purchase Agreement dated as of the date hereof by and between the Parent and Laurus (the “Securities Purchase Agreement”) and (ii) each Related Agreement referred to in the Securities Purchase Agreement (the Securities Purchase Agreement and each Related Agreement, as each may be amended, modified, restated and/or supplemented from time to time, are collectively referred to herein as the “Documents”), or any documents, instruments or agreements relating to or executed in connection with the Documents or any documents, instruments or agreements referred to therein or otherwise, or any other obligations or liabilities of such Company to Laurus, whether now existing or hereafter arising, direct or indirect, liquidated or unliquidated, absolute or contingent, due or not due and whether under, pursuant to or evidenced by a note, agreement, guaranty, instrument or otherwise (all of which are herein collectively referred to as the “Obligations”), and irrespective of the genuineness, validity, regularity or enforceability of such Obligations, or of any instrument evidencing any of the Obligations or of any collateral therefor or of the existence or extent of such collateral, and irrespective of the allowability, allowance or disallowance of any or all of the Obligations in any case commenced by or against any Company under Title 11, United States Code, including, without limitation, obligations or indebtedness of any Company for post-petition interest, fees, costs and charges that would have accrued or been added to the Obligations but for the commencement of such case. Terms not otherwise defined herein shall have the meaning assigned such terms in the Securities Purchase Agreement, as applicable. In furtherance of the foregoing, the undersigned hereby agrees as follows:

1.    No Impairment . Laurus may at any time and from time to time, either before or after the maturity thereof, without notice to or further consent of the undersigned, extend the time of payment of, exchange or surrender any collateral for, renew or extend any of the Obligations or increase or decrease the interest rate thereon, or any other agreement with any Company or with any other party to or person liable on any of the Obligations, or interested therein, for the extension, renewal, payment, compromise, discharge or release thereof, in whole or in part, or for any modification of the terms thereof or of any agreement between Laurus and any Company or any such other party or person, or make any election of rights Laurus may deem desirable under the United States Bankruptcy Code, as amended, or any other federal or state bankruptcy, reorganization, moratorium or insolvency law relating to or affecting the enforcement of creditors’ rights generally (any of the foregoing, an “Insolvency Law”) without in any way impairing or affecting this Guaranty. This Guaranty shall be effective regardless of the subsequent incorporation, merger or consolidation of any Company, or any change in the composition, nature, personnel or location of any Company and shall extend to any successor entity to each Company, including a debtor in possession or the like under any Insolvency Law.

2.    Guaranty Absolute . Subject to Section 5(c) hereof, each of the undersigned jointly and severally guarantees that the Obligations will be paid strictly in accordance with the terms of the Documents and/or any other document, instrument or agreement creating or evidencing the Obligations, regardless of any law, regulation or order now or hereafter in effect in any jurisdiction affecting any of such terms or the rights of any Company with respect thereto. Guarantors hereby knowingly accept the full range of risk encompassed within a contract of “continuing guaranty” which risk includes the possibility that a Company will contract additional obligations and liabilities for which Guarantors may be liable hereunder after such Company’s financial condition or ability to pay its lawful debts when they fall due has deteriorated, whether or not such Company has properly authorized incurring such additional obligations and liabilities. The undersigned acknowledge that (i) no oral representations, including any representations to extend credit or provide other financial accommodations to any Company, have been made by Laurus to induce the undersigned to enter into this Guaranty and (ii) any extension of credit to any Company shall be governed solely by the provisions of the Documents. The liability of each of the undersigned under this Guaranty shall be absolute and unconditional, in accordance with its terms, and shall remain in full force and effect without regard to, and shall not be released, suspended, discharged, terminated or otherwise affected by, any circumstance or occurrence whatsoever, including, without limitation: (a) any waiver, indulgence, renewal, extension, amendment or modification of or addition, consent or supplement to or deletion from or any other action or inaction under or in respect of the Documents or any other instruments or agreements relating to the Obligations or any assignment or transfer of any thereof, (b) any lack of validity or enforceability of any Document or other documents, instruments or agreements relating to the Obligations or any assignment or transfer of any thereof, (c) any furnishing of any additional security to Laurus or its assignees or any acceptance thereof or any release of any security by Laurus or its assignees, (d) any limitation on any party’s liability or obligation under the Documents or any other documents, instruments or agreements relating to the Obligations or any assignment or transfer of any thereof or any invalidity or unenforceability, in whole or in part, of any such document, instrument or agreement or any term thereof, (e) any bankruptcy, insolvency, reorganization, composition, adjustment, dissolution, liquidation or other like proceeding relating to any Company, or any action taken with respect to this Guaranty by any trustee or receiver, or by any court, in any such proceeding, whether or not the undersigned shall have notice or knowledge of any of the foregoing, (f) any exchange, release or nonperfection of any collateral, or any release, or amendment or waiver of or consent to departure from any guaranty or security, for all or any of the Obligations or (g) any other circumstance which might otherwise constitute a defense available to, or a discharge of, the undersigned. Any amounts due from the undersigned to Laurus shall bear interest until such amounts are paid in full at the highest rate then applicable to the Obligations. Obligations include post-petition interest whether or not allowed or allowable.

3.    Waivers .

(a)    This Guaranty is a guaranty of payment and not of collection. Laurus shall be under no obligation to institute suit, exercise rights or remedies or take any other action against any Company or any other person or entity liable with respect to any of the Obligations or resort to any collateral security held by it to secure any of the Obligations as a condition precedent to the undersigned being obligated to perform as agreed herein and each of the Guarantors hereby waives any and all rights which it may have by statute or otherwise which would require Laurus to do any of the foregoing. Each of the Guarantors further consents and agrees that Laurus shall be under no obligation to marshal any assets in favor of Guarantors, or against or in payment of any or all of the Obligations. Each of the undersigned hereby waives all suretyship defenses and any rights to interpose any defense, counterclaim or offset of any nature and description which the undersigned may have or which may exist between and among Laurus, any Company and/or the undersigned with respect to the undersigned’s obligations under this Guaranty, or which any Company may assert on the underlying debt, including but not limited to failure of consideration, breach of warranty, fraud, payment (other than cash payment in full of the Obligations), statute of frauds, bankruptcy, infancy, statute of limitations, accord and satisfaction, and usury.

(b)    Each of the undersigned further waives (i) notice of the acceptance of this Guaranty, of the extensions of credit, and of all notices and demands of any kind to which the undersigned may be entitled, including, without limitation, notice of adverse change in any Company’s financial condition or of any other fact which might materially increase the risk of the undersigned and (ii) presentment to or demand of payment from anyone whomsoever liable upon any of the Obligations, protest, notices of presentment, non-payment or protest and notice of any sale of collateral security or any default of any sort.

(c)    Notwithstanding any payment or payments made by the undersigned hereunder, or any setoff or application of funds of the undersigned by Laurus, the undersigned shall not be entitled to be subrogated to any of the rights of Laurus against any Company or against any collateral or guarantee or right of offset held by Laurus for the payment of the Obligations, nor shall the undersigned seek or be entitled to seek any contribution or reimbursement from any Company in respect of payments made by the undersigned hereunder, until all amounts owing to Laurus by each Company on account of the Obligations are indefeasibly paid in full and Laurus’ obligation to extend credit pursuant to the Documents has been irrevocably terminated. If, notwithstanding the foregoing, any amount shall be paid to the undersigned on account of such subrogation rights at any time when all of the Obligations shall not have been paid in full and Laurus’ obligation to extend credit pursuant to the Documents shall not have been terminated, such amount shall be held by the undersigned in trust for Laurus, segregated from other funds of the undersigned, and shall forthwith upon,