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italics, K1enc -> EncK1 

[Imported from Trac: page NewCaps/WhatCouldGoWrong, version 50]
davidsarah 2009-10-21 00:57:57 +00:00
parent 43fb299f54
commit b497eeed97
1 changed files with 5 additions and 5 deletions
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NewCaps/WhatCouldGoWrong.md

@ -6,16 +6,16 @@ This is about What Could Go Wrong with the "Elk Point 2" immutable file caps: <h
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|#|*what bad thing could happen*|*how*|*who could do it*|*what could they target*|*what crypto property prevents it*|*how expensive to brute force*| |#|*what bad thing could happen*|*how*|*who could do it*|*what could they target*|*what crypto property prevents it*|*how expensive to brute force*|
|1|shape-shifter immutable file [1]footnote|collide read-cap (*R*,*T*)|creator of a file|their own file|the hash function's and cap format's collision resistance on the read-cap (*R*,*T*). This also depends on the encryption of *K1* being deterministic and correct, and on the suitability of hash_r as a KDF (key derivation function).|approx sqrt(2.*p*).2^(*r*+*t*)/2^ [7,8]footnotes| |1|shape-shifter immutable file [1]footnote|collide read-cap (*R*,*T*)|creator of a file|their own file|the hash function's and cap format's collision resistance on the read-cap (*R*,*T*). This also depends on the encryption of *K1* being deterministic and correct, and on the suitability of hash_*r* as a KDF (key derivation function).|approx sqrt(2.*p*).2^(*r*+*t*)/2^ [7,8]footnotes|
|2|unauthorized read|attack the encryption of *K1* with *R*|anyone|any one file|the security of the encryption scheme used for *K1*, the secrecy of the read-key *R*, and the suitability of hash_r as a KDF.|*p*.2^min(*r*,*k*)^| |2|unauthorized read|attack the encryption of *K1* with *R*|anyone|any one file|the security of the encryption scheme used for *K1*, the secrecy of the read-key *R*, and the suitability of hash_*r* as a KDF.|*p*.2^min(*r*,*k*)^|
|3|forgery of immutable file|generate a matching read-cap (*R*,*T*) for someone else's file|anyone|any one file|the hash function's and cap format's second-preimage resistance on (*R*,*T*). This also depends on the encryption of *K1* being deterministic and correct, and on the suitability of hash_r as a KDF.|(*p*/*N*).2^*r*+*t*^ [5,8]footnotes| |3|forgery of immutable file|generate a matching read-cap (*R*,*T*) for someone else's file|anyone|any one file|the hash function's and cap format's second-preimage resistance on (*R*,*T*). This also depends on the encryption of *K1* being deterministic and correct, and on the suitability of hash_*r* as a KDF.|(*p*/*N*).2^*r*+*t*^ [5,8]footnotes|
|4|roadblock or speedbump [2]footnote|generate (*K1enc*,*Dhash*,*V*) that hash to someone else's *T*, and copy their *S*|anyone [6]footnote|any one file|the hash function's and cap format's second-preimage resistance on *T*|(*p*/*N*).2^*t*^| |4|roadblock or speedbump [2]footnote|generate (*EncK1*,*Dhash*,*V*) that hash to someone else's *T*, and copy their *S*|anyone [6]footnote|any one file|the hash function's and cap format's second-preimage resistance on *T*|(*p*/*N*).2^*t*^|
|5|unauthorized read|attack the encryption of the plaintext with *K1*|anyone|any one file|the security of the encryption scheme used for the plaintext, and the secrecy of the encryption key *K1*. The latter also depends on the security and seeding of the RNG that generated it.|*p*.2^*k*^| |5|unauthorized read|attack the encryption of the plaintext with *K1*|anyone|any one file|the security of the encryption scheme used for the plaintext, and the secrecy of the encryption key *K1*. The latter also depends on the security and seeding of the RNG that generated it.|*p*.2^*k*^|
|6|unauthorized read|figure out the input to the hash function that generates *S*|anyone|any one file|the hash function's onewayness for (*R*,*T*) -> *S*|brute force on *R* is !#2| |6|unauthorized read|figure out the input to the hash function that generates *S*|anyone|any one file|the hash function's onewayness for (*R*,*T*) -> *S*|brute force on *R* is !#2|
|7|unauthorized deletion|figure out a working destroy-key *KD* for a given *Dhash*|anyone|any one file|the hash function's preimage resistance on *Dhash* and the secrecy of *KD*|(*p*/*N*).2^min(*d*,*dh*)^| |7|unauthorized deletion|figure out a working destroy-key *KD* for a given *Dhash*|anyone|any one file|the hash function's preimage resistance on *Dhash* and the secrecy of *KD*|(*p*/*N*).2^min(*d*,*dh*)^|
|8|accidental collision|storage indices (*S1*,*T1*) and (*S2*,*T2*) collide accidentally|not applicable|any two files|approximately random distribution of hash function outputs|[4]footnote| |8|accidental collision|storage indices (*S1*,*T1*) and (*S2*,*T2*) collide accidentally|not applicable|any two files|approximately random distribution of hash function outputs|[4]footnote|
|9|denial of service|prevent access to servers holding sufficient shares (by controlling some of them, or by attacking them or the network)|anyone|any file|not prevented by crypto|not applicable| |9|denial of service|prevent access to servers holding sufficient shares (by controlling some of them, or by attacking them or the network)|anyone|any file|not prevented by crypto|not applicable|
|10|cause invalid share to verify|generate (*K1enc*,*Dhash*,*V*) that hash to someone else's (*T*,*U*), and copy their *S*|anyone|any one file|the hash function's second-preimage resistance on (*T*,*U*)|(*p*/*N*).2^*t*+*u*^ [5]footnote| |10|cause invalid share to verify|generate (*EncK1*,*Dhash*,*V*) that hash to someone else's (*T*,*U*), and copy their *S*|anyone|any one file|the hash function's second-preimage resistance on (*T*,*U*)|(*p*/*N*).2^*t*+*u*^ [5]footnote|
|11|undeletion [3]footnote|restore a deleted file's shares by controlling the relevant servers|anyone|any one file|not prevented by crypto|not applicable| |11|undeletion [3]footnote|restore a deleted file's shares by controlling the relevant servers|anyone|any one file|not prevented by crypto|not applicable|
|12|undeletion [3]footnote|generate matching (*R*,*T*,*U*) for a deleted file|anyone|any one file|the hash function's and cap format's second-preimage resistance on (*R*,*T*,*U*)|higher cost than !#3| |12|undeletion [3]footnote|generate matching (*R*,*T*,*U*) for a deleted file|anyone|any one file|the hash function's and cap format's second-preimage resistance on (*R*,*T*,*U*)|higher cost than !#3|