10/10/2001
Security Policy:
Astro Subscriber
Universal Crypto Module
Astro Spectra Plus and XTS5000
Version 01.00.01
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1.0 Introduction 4
1.1 Scope 4
1.2 Overview 4
1.3 Core DigitalUCM Implementation 4
1.4 Core Digital UCM Cryptographic Boundary 4
2.0 FIPS 140-1 Security Level 4
3.0 FIPS 140-1 Approved Operational Modes 5
4.0 Security Rules 5
4.1 FIPS 140-1 Related Security Rules 5
4.2 Motorola Imposed Security Rules 8
5.0 Roles and Services 8
5.1 Core Digital UCM Supported Roles 8
5.2 Core Digital UCM Services 8
6.0 Authentication 9
7.0 Access Control 10
7.1 Security Relevant Data Items (SRDIs) 10
7.2 SRDI Access Types 10
7.3 Services Versus SRDI Access 11
1.0 Introduction
1.1 Scope
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This Security Policy specifies the security rules under which the Astro Subscriber
Universal Crypto Module, herein identified as the Core Digital Universal
Cryptographic Module or Core Digital UCM, must operate. Included in these rules are
those derived from the security requirements of FIPS 140-1 and additionally, those
imposed by Motorola. These rules, in total, define the interrelationship between the:
1. module operators,
2. module services,
3. and security related data items (SRDIs).
1.2 Overview
The Core Digital UCM provides secure key management, Over-the-Air-Rekeying
(OTAR), and voice and data encryption for the Motorola Astro Spectra Plus mobile
radio and XTS5000 portable radio.
1.3 Core Digital UCM Implementation
The Core Digital UCM is implemented as a multi-chip embedded cryptographic
module as defined by FIPS 140-1.
1.4 Core Digital UCM Cryptographic Boundary
The Core Digital UCM is defined as the UCM printed circuit board. This includes
the Armor IC, flash E2
PROM IC, SCI port, SPI port, KVL port, and various support
components and circuitry.
2.0 FIPS 140-1 Security Level
The Core Digital UCM is certified to meet the FIPS 140-1 security requirements for
the levels shown in Table 2.1.
Table 2.1
Core Digital UCM Security Levels
FIPS 140-1 Security Requirements Section Level
1. Cryptographic Module 1
2. Module Interfaces 1
3. Roles and Services 2
4. Finite State Machine Model 1
5. Physical Security 1
6. Software Security 3
7. Operating System Security N/A
8. Key Management 1
9. Cryptographic Algorithms 1
10. EMI / EMC 1
11. Self Tests 1
3.0 FIPS 140-1 Approved Operational Modes
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The Core Digital UCM includes modes of operation that are not FIPS 140-1
approved. Documented below are the configuration settings that are required for the
module to be used in a FIPS 140-1 approved mode of operation:
1. MDC OTAR disabled
2. Key Loss Key (KLK) generation disabled
3. Tamper Enabled
4. DES for encryption, decryption, and MACing shall be used in the following
approved modes: ECB, OFB, CFB, and CBC
5. Use of the following is not FIPS 140-1 approved: DES-XL, DVI-XL, DVI-SPFL,
DVP-XL
4.0 Security Rules
The Core Digital UCM enforces the following security rules. These rules are
separated into two categories, 1) those imposed by FIPS 140-1 and, 2) those imposed
by Motorola.
4.1 FIPS 140-1 Related Security Rules
1. The Core Digital UCM supports the following interfaces:
• Data input interface
a. Synchronous Serial Interface (SSI) - Plaintext Data, Ciphertext Data, Key
Management Data (OTAR), Encrypted Cryptographic Keys (OTAR),
Authentication Data
b. Key Variable Loader (KVL) - Key Management Data, Encrypted
Cryptographic Keys, Plaintext Cryptographic Keys
• Data output interface
a. Synchronous Serial Interface (SSI) - Plaintext Data, Ciphertext Data, Key
Management Data (OTAR)
• Control input interface
a. Synchronous Serial Interface (SSI) - Input Commands
b. Key Variable Loader (KVL) - Input Commands
• Status output interface
a. Synchronous Serial Interface (SSI) - Status Codes
b. Key Variable Loader (KVL) - Status Codes
• Power interface
a. Switched - Powers all circuitry except Battery Backed Register
b. Unswitched - Powers Battery Backed Register
2. The Core Digital UCM inhibits all data output via the data output interface
whenever an error state exists and during self-tests.
3. The Core Digital UCM logically disconnects the output data path from the
circuitry and processes when performing key generation, manual key entry, or
key zeroization.
4. Authentication data (e.g. PINs) and other critical security parameters are entered /
output in plaintext form.
AND
Secret cryptographic keys are entered / output over a physically separate port.
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5. The Core Digital UCM supports a User role and a Cryptographic Officer role.
These two roles have the same set of services.
6. The Core Digital UCM re-authenticates a role when it is powered-up after being
powered-off.
7. The Core Digital UCM provides the following services requiring a role:
• Zeroize Selected Keys
• Transfer Key Variable
• Privileged APCO OTAR
• Change Active Keyset
• Change Password
• Encrypt Securenet
• Decrypt Securenet
• Encrypt Digital
• Decrypt Digital
8. The Core Digital UCM provides the following services not requiring a role:
• Initiate Self Tests
• Zeroize all keys
• Non-Privileged APCO OTAR
• Zeroize All Keys and Password
• Reset Crypto Module
• Shutdown Crypto Module
• Extract Log
• Clear Log
• Download RSS
• Clear Bypass
• Key/Keyset Check
• Program Update
9. The Core Digital UCM enforces Role-Based identification.
10. The Core Digital UCM implements all software using a high-level language,
except the limited use of low-level languages to enhance performance.
11. The Core Digital UCM protects secret keys and private keys from unauthorized
disclosure, modification and substitution.
12. The Core Digital UCM provides a means to ensure that a key entered into, stored
within, or output from the Core Digital UCM is associated with the correct
entities to which the key is assigned. Each key in the Core Digital UCM is
entered and stored with the following information:
• Key Identifier – 16 bit identifier
• Algorithm Identifier – 8 bit identifier
• Key Type – Traffic Encryption Key or Key Encryption Key
• Physical ID, Common Key Reference (CKR) number, or CKR/Keyset
number – Identifiers indicting storage locations.
Along with the encrypted key data, this information is stored in a key record that
includes a CRC over all of the fields to detect data corruption. When used or
deleted the keys are referenced by Key ID/Algid, Physical ID, or CKR/Keyset.
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13. The Core Digital UCM denies access to plaintext secret and private keys
contained within the Core Digital UCM.
14. The Core Digital UCM provides the capability to zeroize all plaintext
cryptographic keys and other unprotected critical security parameters within the
Core Digital UCM.
15. The Core Digital UCM supports the following FIPS approved algorithms:
• DES
- OFB for symmetric encryption / decryption of digital voice, data, and
Project 25 OTAR
- 1-Bit CFB for symmetric encryption / decryption of analog voice
- CBC for MACing of Project 25 OTAR and software upgrades
- ECB for symmetric decryption of Project 25 OTAR
• 3DES
- 8-bit CFB for symmetric encryption / decryption of keys and parameters
stored in the internal database
- CBC for symmetric decryption of software upgrades
16. The Core Digital UCM, when used in the Astro Spectra and XTS5000, conforms
to all FCC requirements for radios.
17. The Core Digital UCM performs the following self-tests:
• Power-up and on-demand tests
- Cryptographic algorithm test: Each algorithm is tested by using a known
key, known data, and if required a known IV. The data is then encrypted;
the encrypted data is then decrypted. The test passes if the final data
matches the known data, otherwise it fails.
- Software/firmware test: The software firmware test calculates a checksum
over the code. The checksum is calculated by summing over the code in
32 bit words. The code is appended with a value that makes the checksum
value 0. The test passes if the calculated value is 0, otherwise it fails.
- Critical Functions test.
- LFSR Test: The LFSRs are tested by setting the feedback taps to a
known value, loading them with known data, shifting the LFSR 64
times, then comparing the LFSR data to a known answer. The test
passes if the final data matches, otherwise it fails.
- General Purpose RAM Test: The general purpose RAM is tested for
stuck address lines and stuck bits. This is accomplished through a
series of operations that write and read the RAM. The test passes if all
values read from the RAM are correct, otherwise it fails.
Powering the module off then on or resetting the module using the Reset
service will initiate the power-up and on-demand self tests.
• Conditional tests
- Software/firmware load test: A MAC is generated over the code when it is
built using DES-CBC. Upon download into the module, the MAC is
verified. If the MAC matches the test passes, otherwise it fails.
- Continuous Random Number Generator test: The continuous random
number generator test is performed on 3 RNGs within the module. The
first is a hardware RNG which is used to seed the ANSI X9.17 PRNG and
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the maximal length 64-bit LFSR. The second is an implementation of
Appendix C ANSI X9.17 which is used for key generation, and the third
is a maximal length 64-bit LFSR which is used for IV generation. For
each RNG, an initial value is generated and stored upon power up. This
value is not used for anything other than to initialize comparison data.
Successive calls to any one of the RNGs generates a new set of data,
which is compared to the comparison data. If a match is detected, this test
fails, otherwise the new data is stored as the comparison data and returned
to the caller.
18. The Core Digital UCM enters an error state if the Cryptographic Algorithm Test,
LFSR Test, Continuous Random Number Generator Test, or the General Purpose
RAM Test fails. This error state may be exited by powering the module off then
on.
19. The Core Digital UCM enters an error state if the Software/Firmware test fails.
As soon as an error indicator is output via the status interface, the module
transitions from the error state to a state that only allows new software to be
loaded.
20. The Core Digital UCM enters an error state if the Software/Firmware Load test
fails. This state is exited as soon as an error indicator is output via the status
interface.
21. The Core Digital UCM outputs an error indicator via the status interface
whenever an error state is entered due to a failed self-test.
22. The Core Digital UCM does not perform any cryptographic functions while in an
error state.
4.2 Motorola Imposed Security Rules
1. The Core Digital UCM does not support multiple concurrent operators.
2. The cryptographic module will continue to provide User Role and Crypto Officer
Role services until the module has been powered down.
3. All cryptographic module services are suspended during key loading.
4. After a sufficient number (15) of consecutive unsuccessful user login attempts, the
module will zeroize all keys from the Key Database.
5. Upon detection of a critically low voltage condition on the switched power supply,
the cryptographic module shall erase all plaintext keys.
6. Upon detection of a critically low voltage condition on the unswitched power
supply, the cryptographic module shall erase all SRDIs.
7. Upon detection of tamper, the cryptographic module shall erase all SRDIs.
8. The module shall at no time output any security related data items (SRDIs)
5.0 Roles and Services
5.1 Core Digital UCM Supported Roles
The Core Digital UCM supports two (2) roles. These roles are defined to be:
• the User Role,
• the Cryptographic Officer (CO) Role
5.2 Core Digital UCM Services
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• Transfer Key Variable: Transfer key variables and/or zeroize key variables
to/from the Key Database via a Key Variable Loader (KVL). Available to
User and CO Roles.
• Privileged APCO OTAR: Modify and query the Key Database via APCO
OTAR Key Management Messages. Available to User and CO Roles.
• Change Active Keyset: Modify the currently active keyset used for selecting
keys by PID or CKR. Available to User and CO Roles.
• Change Password: Modify the current password used to identify and
authenticate the User and CO Roles. Available to User and CO Roles.
• Encrypt Securenet: Encrypt 12 Kb analog voice. Available to User and CO
Roles.
• Decrypt Securenet: Decrypt 12 Kb analog voice. Available to User and CO
Roles.
• Encrypt Digital: Encrypt digital voice or data. Available to User and CO
Roles.
• Decrypt Digital: Decrypt digital voice or data. Available to User and CO
Roles.
• Clear Bypass: Allows the clear bypass of voice or data streams. Available to
User and CO Roles.
• Initiate Self Tests: Performs module self tests comprised of cryptographic
algorithms test, software firmware test, and critical functions test. Initiated by
module reset or transition from power off state to power on state. Available
without a Role.
• Zeroize Selected Keys: Zeroize selected key variables from the Key Database
by Physical ID (PID) or Common Key Reference (CKR). Available to User
and CO Roles.
• Zeroize all keys: Zeroize all keys from the Key Database. Available without a
Role. (Module can be reinitialized using KVL)
• Zeroize All Keys and Password: Zeroizes all keys and SRDIs in the key
database. Resets the password to the factory default. Allows user to gain
controlled access to the module if the password is forgotten. Available
without a Role. (Module can be reinitialized using KVL)
• Non-Privileged APCO OTAR: Hello and Capabilities Key Management
Messages may be performed without a Role.
• Reset Crypto Module: Soft reset of module to remove module from error
states. Available without a Role.
• Shutdown Crypto Module: Prepares module for removal of power. Available
without a Role.
• Extract Log: Status Request. Provides detailed history of error events.
Available without a Role.
• Clear Log: Clears history of error events.
• Download RSS: Download configuration parameters used to specify module
behavior. Examples include enable/disable APCO OTAR, SingleKey or
MutliKey mode, etc. Available without a Role.
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• Key/Keyset Check: Obtain status information about a specific key/keyset.
Available without a Role.
• Program Update: Update the module software. Available without a Role.
6.0 Authentication
The Core Digital UCM uses a 40-bit password to authenticate the User and CO
roles. The password is initialized to a default value during manufacturing. After
authenticating, the password may be changed at any time. Fifteen consecutive invalid
authentication attempts erases all keys from the Key Database.
7.0 Access Control
7.1 Security Relevant Data Items (SRDIs)
Table 7.1
SRDI Definition
SRDI Identifier Description
Key Protection Key
(KPK)
Key used to encrypt the database and other non-volatile
parameters
Plaintext Traffic
Encryption Keys ( TEKs)
Keys used for voice and data encryption
Plaintext Key Encryption
Keys
Keys used encryption of keys in OTAR
Plaintext MAC Key Key used for authentication of software upgrade. Stored in
non-volatile memory
Plaintext Password User password entered during user authentication
7.2 SRDI Access Types
Table 7.2
SRDI Access Types
SRDI Access Type Description
Retrieve key Decrypts encrypted TEKs or KEKs in the database using the
KPK and returns plaintext version
Store key Encypts plaintext TEKs or KEKs using the KPK and stores the
encrypted version in the database
Erase Key Marks encrypted TEK or KEK data in key database as invalid
Create KPK Generates and stores new KPK
Store Password Hashes user password and stores it in the database
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7.3 Access Matrix
Table 7.3
SRDI versus SRDI Access
SRDI Access
Operation
Applicable
Role
User Service
Retrieve
Key
Store
Key
Erase
Key
Create
KPK
Store
Pin
User
Role
Crypto
Officer
Role
No
Role
Required
1. Transfer Key Variable X X X X
2. Privileged APCO OTAR X X X X X
3. Change Active Keyset X X
4. Change Password X X X X X
5. Validate Password X X X
6. Encrypt Securenet X X X
7. Decrypt Securenet X X X
8. Encrypt Digital X X X
9. Decrypt Digital X X X
10. Clear Bypass X X X
11. Initiate Self Tests X X X
12. Zeroize Selected Keys X X X
13. Zeroize All Keys X X X X
14. Zeroize All Keys and Password X X X X X X
15. Non-Privileged APCO OTAR (not for
key entry)
X X X
16. Reset X X X
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SRDI Access
Operation
Applicable
Role
17. Shutdown X X X
18. Extract Log X X X
19. Clear Log X X X
20. Download RSS X X X X X
21. Key/Keyset Check X X X
22. Program Update X X X X X X