| Format |
Representation |
Examples |
| Fuzzy |
undefined/marginal/complete, don't
know/untrustworthy/marginal/full |
PGP's direc trust |
| Fuzzy |
very trustworthy/trustworthy/untrustworthy/very
untrustworthy |
Ruth/Xu/Bhargava/Regnier's RT0 |
| General |
Lattice |
Moreton/Twigg |
| General |
Binary (yes, no) + possible supplementary information |
Trust management (Blaze/Feigenbaum's PolicyMaker and KeyNote) |
| Integer |
Virtual currency {0..infinity} |
Trustos in ubiquitous computing (http://www.trustos.com); maybe
the Nuglets in mobile ad-hoc networks
(http://www.lst.inf.ethz.ch/research/publications/publications/COM_MAG_2001/COM_MAG_2001.pdf) |
| Integer |
{-infinity..infinity} |
Slashdot.org's Karma; Ebay's feedback rating |
| Integer |
1-10 |
FOAF trust module -
http://trust.mindswap.org/trustOnt.shtml |
| Integer |
{0..infinity} |
Chimaera (Tarah, Huitema); Free Haven (www.freehaven.net, Dingledine)
direct and meta trust; Li Gong system and direct trust; PGP's parameters (number
of agents); Advogato's trust metric |
| Integer |
{1..infinity} |
Ueli Maurer's deterministic trust |
| Integer |
{-1..4} |
Abdul-Rahman/Hailes; Poblano
(www.jxta.org/docs/trust.pdf) |
| Logical |
Binary (true, false) |
Cryptographic logics (Burrows/Abadi/Needham' BAN,
Gong/Needham/Yahalom's GNY, Syverson/van Oorschot's SvO); Freenet
(www.freenetproject.org); Lars Rasmusson/Sverker Jansson; P. Venkat
Rangan.; SPKI |
| Logical |
trust(trustor,trustee,action,level) where level is in
{-100;100} |
Grandison/Sloman's SULTAN |
| Logical |
trustBL(trustor,service,trustee,,depth,blacklist) where depth
is in {0..infinity} + {*} (* for ) |
Giorgini/Massaci/Mylopoulos/Zannone |
| Logical |
formulas |
Demolombe/Jones logics; Walt Teh-Ming Yao's Fidelis |
| Matrix |
Table |
Yao-Hua Tan |
| Real |
[0;1] |
Ueli Maurer's probabilistic trust; Neurogrid (www.neurogrid.net, Samuel
Joseph); Sierra's (sierra.openprivacy.org, OpenPrivacy) System trust;
Castelfranchi/Falcone/Pezzulo's trustfulness |
| Real |
[0;1[ |
BBK (Beth, Borchedring, Klein) direct trust |
| Real |
]0;1[ |
IST (Jamil, Sadri, Shiri) |
| Real |
[-1;1] |
Marsch (http://citeseer.ist.psu.edu/marsh94formalising.html);
Sierra's (sierra.openprivacy.org, OpenPrivacy) interpersonal and self
trust |
| Vector |
Tuple (each component in [0;1]) |
Josang's opinions (belief/disbelief/uncertainty/atomicity);
Narendar Shankar/William A. Arbaugh; Golbeck/Hendler/Parsia (minimum,
maximum, and weighted average trust); SECURE (support, inconclusive,
contradict) |
| Vector |
Emotional Bank Account (EBA) Tuple of 3 fields in a given virtual currency
(amount of money paid by the trustee in terms of actions; money lost due to
these actions; some money, which is not yet known to be gained or lost) |
Trustee's EBA(100,12,4): the trustor has gained 100 trustos from this
trustee, lost 12 trustos and 4 trustos are still not processed
(http://www.cs.tcd.ie/publications/tech-reports/reports.04/TCD-CS-2004-37.pdf)
; the term Emotional Bank Account is from Stephen Covey's 7 habits of highly
effective people |