CSD 3324 SP (AES 256-bit)

CSD 3324 SP Secure Telephone and Fax Encryption System

CSD 3324 SP Secure Voice Telephone and Fax Encryption - AES 256-bit

The CSD 3324 SP Secure Voice Telephone and Fax Encryption system provides integrated voice and fax secure communications for mission-critical government, corporate and private applications. It secures voice conversations as well as connects to any Group 3 fax machine for secure fax communications. Using the AES 256-bit encryption algorithm and Diffie-Hellman public key exchange key management, the CSD 3324 SP offers proven cryptographic strength, and ease of deployment and operation. The CSD 3324 SP Secure Voice Telephone and Fax Encryption system is interoperable with TCC's CSD 3324 SPF secure fax encryptor and the CSD 3324 SPV secure phone, which is the voice-only version of the CSD 3324 SP.


  • Strategic-level security for voice and fax communications
  • Excellent recovered voice quality
  • Easily connects to any Group 3 fax machine
  • AES 256-bit with Diffie-Hellman public key exchange for simplity, cryptographic strength and ease of use
  • Interoperable with TCC's CSD 3324 SPF fax encryptor
  • Auto-sensing incoming plain or secure fax
  • User-friendly menu-based set up (may be password protected)
  • Secure and non-secure modes; password protected secure-only mode
  • Stored phone numbers: 50 names and phone numbers; last number redial
  • Auto-answer/fax sense: user configurable number of rings

Integrated Voice and Fax Security

The CSD 3324 SP secures voice and fax communications in a single telephone package. The CSD 3324 SP has a fallback mode that was originally developed for poor HF channels. As a result, secure communications are possible even over degraded line conditions. Its 9,600 bps MPLP vocoder provides excellent recovered voice quality with automatic fallback to 4,800 bps CELP as needed.

A universal, 2-wire RJ-11 fax interface is provided on the phone enabling fax encryption regardless of the chosen brand of Group 3 fax used. The fax capability is auto-answering and auto-sensing, allowing incoming calls to be screened by the telephone. If the call is not a fax call, the telephone "rings" giving the user a second chance to answer any incoming voice calls.

Incoming and outgoing plain (non-secure) and secure fax communications, or secure-only fax mode are supported. Secure fax and voice communication modes may be password restricted. Without the password, the CSD 3324 SP functions in only non-secure mode. User-friendly menus, which may be password protected, provide logical set-up of the CSD 3324 SP's voice answering and fax handling options.

Cryptographic Strength

The CSD 3324 SP protects voice and fax calls using Advanced Encryption Standard (AES) encryption engines seeded using Diffie-Hellman public key auto-negotiated 256-bit session keys, and path-independent initialization vectors.

Public Key management: Diffie-Hellman (D-H) Public Key negotiated session keys and Initialization Vectors (IVs); 1,024-bit D-H modulus; six authentication characters used to prevent 'man-in-the-middle' attacks.

Key generator: AES 256-bit session keys; dual AES key generators, full-duplex and path-unique IVs

Secure Voice and Fax CSD 3324 SP Network Encryption

Secure Voice and Fax Encryption Specifications

Phone Numbers

 50 names and phone numbers

 last number redial feature

Auto-Answer/Fax Sense

 user configurable number of rings

Display and keypad

 2 lines × 16 characters LCD display

 20 push-button keypad

  • 12 button standard telephone keypad
  • 8 function key buttons

Security features

 secure mode password

 menu access password protection


 100-240 V AC, 50/60 Hz, 9.5 W (nom)

 auxiliary DC power, primary or as backup to AC, 10-30 V DC 7 W (nom)

Physical Dimensions

  Height: 10.3 cm

 Width: 31.3 cm

 Depth: 27.2 cm

 Weight: 2.32 kg unpacked

Line Side
"Black" Interface

 Telephone line interface - two-wire, RJ-11 phone line I/O

"Red" Interfaces

 Fax interface: Two-wire, RJ-11 facsimile I/O, Group 3 (9.6, 7.2, 4.5, 2.4 Kbps)

 Voice interface:

  • Four-wire handset analog signal port (modular RJ-8)
  • Voice digitization (vocoders): 9.6Kbps MPLP, 4.8Kbps CELP (fallback)


 CSD 3324 SPV voice-only model

 CSD 3324 SP and SPV available in Beige or Black


TCC is dedicated to quality products and services. TCC is ISO 9001 certified. ISO 9001, granted to TCC by TUV, is the most stringent standard available for total quality systems in design/development, production, installation and servicing.

Cipher One

CipherONE® Optimized Network Encryption

Our solutions meet TCC's CipherONE Optimized Network Encryption best-in-class criteria for maximum cryptographic strength, and are optimized for performance and ease of use for our customers.

Read More