Cryptography – Particular algorithmic function encoding – Nbs/des algorithm
Patent
1992-09-22
1994-10-18
Cangialosi, Salvatore
Cryptography
Particular algorithmic function encoding
Nbs/des algorithm
380 3, 371 223, H04L 900
Patent
active
053575725
ABSTRACT:
A set/scan test capability is provided for a circuit that includes sensitive subcircuits, but that can be latched out to prevent reverse engineering the sensitive elements. A mechanism to inhibit set/scan test access to at least some of the sensitive subcircuits is selectively actuated by a control circuit to override a normal set/scan test and inhibit set/scan access to the sensitive subcircuits. Various implementations are possible, such as fusible-link PROMs for irreversibly inhibiting set/scan access to the sensitive subcircuits after an initial non-inhibited test period, the use of encryption codes to enable repeated set/scan access to the sensitive subcircuits, and an erasable/reprogrammable mechanism for inhibiting set/scan access to programmed sets of subcircuits.
REFERENCES:
patent: 4139864 (1979-02-01), Schulman
patent: 4267578 (1981-05-01), Vetter
patent: 4603381 (1986-07-01), Guttag
patent: 4833676 (1989-05-01), Koo
patent: 5109190 (1992-04-01), Sakashita et al.
Baukus James P.
Bianco Mark E.
Dwyer Douglas A.
Knobbe David J.
Kramer Allan R.
Cangialosi Salvatore
Denson-Low W. K.
Hughes Aircraft Company
LandOfFree
Apparatus and method for sensitive circuit protection with set-s does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for sensitive circuit protection with set-s, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for sensitive circuit protection with set-s will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2378568