COMMITTEE TR45 LAES AdHoc Group
TR45 LAES/2002.06.25.14
June 25, 2002 in Dallas, Texas
CONTRIBUTION
TITLE:
Improvement to Decryption/Decompression Language in PN-4465Rv1
SOURCE:
AT&T Wireless Services
Peter Musgrove
425-580-6875
peter.musgrove@attws.com
___________________________________________________________
ABSTRACT
This contribution adds needed clarification to decryption/decompression language in PN4465Rv1.
NOTICE
This contribution has been prepared to assist Technical Subcommittee TIA TR-45. This document is offered
to the subcommittee as a basis for discussion and is not binding on AT&T Wireless Services, Inc. AT&T
Wireless Services, Inc. specifically reserves the right to add to, or amend, the statements contained herein.
The contributor grants a free, irrevocable non-exclusive license to the Telecommunications Industry
Association (TIA), to incorporate text contained in this contribution and any modifications thereof in the
creation of a standards publication; to copyright in any standards publication even though it may include
portions of this contribution; and, at TIA’s, discretion, to permit others to reproduce in whole or in part the
resulting standards publication.
1 Introduction
The FBI CIS contribution TR45 LAES 2002.05.21.03 contains the following three
paragraphs:
When the TSP provides or controls the encoding for the intercept subject’s communications
or at least is knowledgeable of this processing, the TSP shall transmit the communications
content, when authorized, toward the LEA Collection Function in a decoded form.
When the TSP provides or controls the compression for the intercept subject’s
communications or at least is knowledgeable of this processing, the TSP shall transmit the
communications content, when authorized, toward the LEA Collection Function in a
decompressed form.
When the TSP provides or controls the encryption for the intercept subject’s
communications or at least is knowledgeable of this processing, the TSP shall transmit the
communications content, when authorized, toward the LEA Collection Function in a
decrypted form.
AWS disagrees with the notion that CALEA requires a TSP to perform the functions described in
the three paragraphs above.
2
Discussion
Encryption/Decryption: The existing text in PN-4465Rv1 appropriately handles the decryption
requirement by allowing a TSP to provide information necessary to decrypt to law enforcement
such that law enforcement actually performs the decryption. CALEA is clear on this issue.
Encoding/Decoding: There is no general “encoding/decoding” requirement in CALEA or in PN4465Rv1; AWS believes that no text describing encoding/decoding should be added to PN4465Rv1.
Compression/Decompression: PN-4465Rv1 currently contains a decompression requirement
that is handled in a manner similar to decryption. There is no general
“compression/decompression” requirement in CALEA. Nevertheless, without arguing whether
decompression is required by CALEA or not, the existing text for both decryption and
decompression can stand some improvement.
3 Recommendation
Section 4.6.3 of PN-4465Rv1 currently contains the following text:
“A TSP shall not be responsible for decrypting or decompressing, or ensuring the government's
ability to decrypt or decompress, any communication encrypted or compressed by a subscriber or
customer, unless the encryption or compression was provided by the TSP and the TSP possesses
the information necessary to decrypt or decompress the communication.”
This contribution recommends an improvement to the above text by the addition of the
following sentence immediately after the text referenced above:
“A TSP that provides the government with information about how to decrypt or
decompress a communication (e.g., identifying the type of compression software used to
compress the communication, directing the government to the appropriate vendor that can
provide decryption or decompression equipment, or providing the encryption key used to
encrypt the communication) fully satisfies its obligation under the preceding sentence."