| 291 | | * Alice fetches DSDB key at IS |
| 292 | | |
| 293 | | DSDB_KEY_REQUEST |
| 294 | | DSDB_KEY_PASS(keycertificate) |
| 295 | | |
| 296 | | * Wallet Alice sends obfuscated blanks (coins without signature and with serial |
| 297 | | encrypted for DSDB) with the serial to Wallet Bob (Wallet Alice now needs to wait a while) |
| 298 | | |
| 299 | | { |
| 300 | | standard identifier = http://opencoin.org/OpenCoinProtocol/1.0 |
| 301 | | currency identifier = http://opencent.net/OpenCent |
| 302 | | denomination = denomination |
| 303 | | key identifier = key_id(signing key) |
| 304 | | serial = base64(encrypt(ALG,pub-key-of-DSDB, serial)) |
| 305 | | } |
| 306 | | |
| 307 | | BLANK_PRESENT( dsdb_keycertificate list(blank1, blank2, ...) ) |
| 308 | | XXX remove crypto reference |
| 309 | | |
| 310 | | * Wallet Bob check: |
| 311 | | |
| 312 | | * Wallet Bob validates the blanks |
| 313 | | - do we have the "currency description document" |
| 314 | | - do we trust the issuer (do we have a valid public key) |
| 315 | | - checks blanks against cdd |
| 316 | | |
| 317 | | * If blanks are invalid, the transfer is declined by Wallet Bob |
| 318 | | (later: cdd transfer between wallets) |
| 319 | | |
| 320 | | * Wallet Bob shows proposed transfer to Bob |
| 321 | | |
| 322 | | * Bob decides whether to |
| 323 | | - accept transfer (trust issuer, enough currency) |
| 324 | | - accept transfer without double spending checking |
| 325 | | - decline transfer |
| 326 | | |
| 327 | | BLANK_REJECT( list( (encrypted_serial_blank1, "Reason1"), ... ) ) |
| 328 | | BLANK_REJECT( emptylist, "Reason") |
| 329 | | |
| 330 | | if DSDB is required (normal case): |
| 331 | | |
| 332 | | * Wallet Bob prepares for coin exchange with IS, by creating blanks of same sum (see #3) |
| 333 | | |
| 334 | | * Wallet Bob DSDB lookup |
| 335 | | - parse cdd for issuer service location |
| 336 | | - parse blanks for necessary minting key ids |
| 337 | | - start session with authenticated issuer service (IS) (secured and authenticated by transport layer, e.g. SSL) |
| 338 | | - get all missing minting key certs (MINTING_KEY_FETCH_KEYID) |
| 339 | | - IS sends key certs or rejects a key id (unknown, outdated) (MINTING_KEY_PASS/FAILURE) |
| 340 | | - lock list of encrypted coin serial numbers at IS (DSDB) |
| 341 | | LOCK_COIN_REQUEST( DSDB_key_key_id, transaction_id, |
| 342 | | list( (key_identifier1, encrypted_serial1), ... ) ) |
| 343 | | |
| 344 | | - IS either accepts with locking time or rejects with list of rejected serials + reason (locked, spent) |
| 345 | | If all coins lock: |
| 346 | | LOCK_COIN_ACCEPT(transaction_id, lock_expires) |
| 347 | | If some coins cannot lock, no coins are locked. |
| 348 | | LOCK_COIN_FAILURE(transaction_id, list( (key_identifier1, encrypted_serial1, "Reason1"), ...)) |
| 349 | | |
| 350 | | Reasons: |
| 351 | | |
| 352 | | Key ID of DSDB is unknown or expired Permanant |
| 353 | | Key ID of blank is unknown or expired Permanant |
| 354 | | Decryption of serial failed Permanant |
| 355 | | Serial already spent Permanant |
| 356 | | Serial locked (not spent) Temporary |
| 357 | | |
| 358 | | |
| 359 | | (this part pauses, session is kept) |
| 360 | | |
| 361 | | * Wallet Bob tells Wallet Alice accept or reject with reason (unknown, outdated, locked, spent) for each rejected blank |
| 362 | | (if one blank is rejected the whole transfer has to be rejected) (future: bob signs receipt) |
| 363 | | |
| 364 | | BLANK_FAILURE( list( (encrypted_serial_blank1, "Reason1"), ...)) |
| 365 | | BLANK_FAILURE( emptylist, "Reason") |
| 366 | | |
| 367 | | BLANK_ACCEPT |
| 368 | | |
| 369 | | Note: After BLANK_ACCEPT, a BLANK_REJECT(emptylist, "Reason) can be given to abort the transaction until |
| 370 | | COIN_SPEND is sent |
| 371 | | |
