Onion Aeon Blockchain Explorer

(no javascript - no cookies - no web analytics trackers - no images - open sourced)

Tx hash: 679de32c3c2aeac20a1c863bb48016b56d3e9aa4fd4dc7f476dfa8db230d38ef

Tx prefix hash: 6025c366f87f36483d575141ce900f9f80ddbdd40e8d48d0ca1c700f439bdc18
Tx public key: 2b435b2b60246d62d21a523ca095260cee4a35eedd41d95a61cfc52de2c2417c
Timestamp: 1528510118 Timestamp [UCT]: 2018-06-09 02:08:38 Age [y:d:h:m:s]: 08:067:03:01:59
Block: 965589 Fee (per_kB): 0.017000000000 (0.005604636188) Tx size: 3.0332 kB
Tx version: 1.0 No of confirmations: 1059123 RingCT/type: no
Extra: 012b435b2b60246d62d21a523ca095260cee4a35eedd41d95a61cfc52de2c2417c

40 output(s) for total of 9.093000000000 AEON

stealth address amount amount idx
00: aa702f7c10e90bcac85abbfc5b3af8576b89acae8ddec2d69693aca772d389e4 0.500000000000 621488 of 901330
01: 09e9725be9f606d6641162e1f0ef40e0edcef8106cafc5f01aabdec5639683dc 0.008000000000 183244 of 492648
02: f13ef8e1fb8d80e57f99b272ef6b51d3aaae3e27b94cc6455bd5517c5e9bf4cf 0.500000000000 621489 of 901330
03: 15a1d51dccdea5fd2946e7305abced7063b643d92e6bd9258a5fed4aa8bd10bd 0.007000000000 183870 of 405219
04: 595c901272839bfdb87cf47ae9cbd43bea250ed278ca56472429beff6eedb107 0.005000000000 289968 of 470331
05: 6d7dca2a4efe31ebe8774a05cc4cb9cb06fb60ad0c0ae1b6dc867c9c0365ba4f 0.500000000000 621490 of 901330
06: 8b05e13c557ad45fb637ecef1403f501e79f85303047d5755b01d0a7ecce58f7 0.006000000000 185710 of 398779
07: 4d70f2d46babdc141934468731c4df28281999774c63d6c58b5c2a435bd38b2b 1.000000000000 457732 of 1370820
08: 7468ec03feeb70b87a7dca67bd07e443eafa247573719c895a9854caa4de8b1f 0.004000000000 184182 of 360059
09: 2473cfab5ea06c8f27f7aca94ccd3549b147b8e846d85ab75f403cd2311a1ffa 0.005000000000 289969 of 470331
10: 76e3121fc6d0cfb82f61ce228c810ff3fcb35b6d77149d2e9234850b03109471 0.030000000000 287505 of 469486
11: 51d163959030ae70236e1d3a580ea6525dfb017d22da172456434dbb2f3dff3c 0.200000000000 363811 of 1117191
12: dd00348e32933b8e3e886fb9f6597f2aa87416a457ca2b57136964b1eafc6792 0.500000000000 621491 of 901330
13: c317ff95bec6478791459f0d6951cac45ce47318e751d38040dcc1b2d6ad59a2 0.006000000000 185711 of 398779
14: ac6239ce516046770e129ea44b345178720985322eca48a0de91d7cbb86d119c 0.020000000000 308761 of 534270
15: cd1d5fcf23f1da1608b2045d18122cad5a0887b448a3a527f6c2fc9f715adb8d 0.009000000000 212972 of 741386
16: 7c1509c886e92c7bd57075a313923a2c7caca71b2b359df3ba27ffe4c31d6dbc 0.010000000000 333126 of 670764
17: fbaac575fff948faf49db22c7ecdad61e08eb2a081ccbacc9dc3cfe4d828cb30 0.060000000000 269739 of 450750
18: 03fd8ecd6cec4a9d1b8745bdd3cb4dead8f5c212254e5f5f09f604fe378d0028 0.600000000000 336147 of 515187
19: 82d2c03f153ebf9be5c0dc72dfe9a94a3440a2b15416c3c7af9670f4290e7d2b 0.020000000000 308762 of 534270
20: 68f822e501b61af08cb81d90f603d18b3e8a13f7e126adbada4baf94ff99006d 0.500000000000 621492 of 901330
21: 70b818fc2468c7dfdabe98d7f52accbe0e433305938c40a7341f37df79630158 0.010000000000 333127 of 670764
22: 267ab2d21688d49c803cc86f86b1d51698f112946df046821ce4fd4f72c150ab 0.040000000000 287830 of 472373
23: e7d16fd0a6e147ab674b714cebf55d61a86614e7fc5c65e3e9d94ccb0842453f 0.030000000000 287506 of 469486
24: 9cc7dd0282231f8943d2022765feb8473afe0cfa79e291f30dbd952be69500c0 0.500000000000 621493 of 901330
25: b2a69e6a55277a742545d9c4e818d9a734feb995866034ec09bf4afd49b98026 0.500000000000 621494 of 901330
26: 24486a3135402e5de795f2470c4e20c93623da83c9ab32bc02f105aae17db8a2 0.500000000000 621495 of 901330
27: 2427fafb95bd78cd0ab839f9b32a96d25c9564ab0b5bdeef8b38f1d37175f85f 0.030000000000 287507 of 469486
28: f6d0dc03dd0feeb9e4c04669af72451349aa263de9364c5710e5f2e2994f6d41 0.002000000000 181881 of 278530
29: 7073ef882be95d986e2cde0e6e2bb5c1c23d95d53089966213871ab428751ce5 0.500000000000 621496 of 901330
30: 8cab5798fdb6236ff4efd477d3150e2f56f060140a5128135600b0c617a47e92 0.090000000000 380248 of 869710
31: b70e636c023b44a0a21dfb45caa583610eebf1d96f3ef0d53c0b6ee8ea353c2c 0.500000000000 621497 of 901330
32: bf705738925c35617a885892c93815fa4dd6399463b15420f5973f02c6dc99e9 0.007000000000 183871 of 405219
33: f8ebc611e3fd1cd6550a5e836942683259f4d262dcf940306f794cdc79402944 0.500000000000 621498 of 901330
34: c493b9078dc76ee1120b0c625551f72c8cd3b814365e9beec2beb9ce741fbacf 0.001000000000 187387 of 287058
35: 153663115b597a01f74d2dc86b552fab948892e1e05e2f37b4b52f68b1cd3ea1 0.004000000000 184183 of 360059
36: 454d36fc17c3886350ee27d3181ded5d0d48cc6ab17e6f766dbd66bc75a55c0a 0.080000000000 272939 of 516262
37: 64371dba351f1b0ddb2c3d7c737130cdb6ab9c180f64f92f3acc9f5febb08c87 0.500000000000 621499 of 901330
38: 44cadda5a3f4c50a84705e792aac489ab58a2fc8fcfe8c47396c6fa9f0a2c059 0.800000000000 271918 of 454505
39: 7156df0bb9e5357850bf7fc6fe7ea0eb4b5cfbacd951ef6a57c51c30421e7991 0.009000000000 212973 of 741386

Check which outputs belong to given Aeon address/subaddress and viewkey

For RingCT transactions, outputs' amounts are also decoded
Note: address/subaddress and viewkey are sent to the server, as the calculations are done on the server side



Prove to someone that you have sent them Aeon in this transaction

Tx private key can be obtained using get_tx_key command in aeon-wallet-cli command line tool
Note: address/subaddress and tx private key are sent to the server, as the calculations are done on the server side



Inputs' ring size time scale (from 2014-07-04 00:06:54 till 2018-06-09 02:15:31; resolution: 8.45 days)

  • |_________________________*_______________________________________________________________________________________________________________*______*________________________*|
  • |_*______________________________________________________________________________________________________________________________________________*________________________*|
  • |______________________________________________________________________________________________________________________________________________________________________*_**|
  • |_______________________________________________________________________________________________________________________*_______________________________________*_*_______*|
  • |________________________________________________________________________________________________________________________________________*________________________________*|

5 inputs(s) for total of 9.110000000000 AEON

key image 00: f19966b25cada4c099197ce02a9f523ddc2946d2508e0b4281b8730f08631ba6 amount: 0.010000000000
ring members blk ring size in/out timestamp age [y:d:h:m:s]
- 00: df97c4661669311a4cff0bfc97e2826867c22de2c64e8468fc5b7d173a41a4b5 00324604 0 0/9 2015-01-27 20:22:28 11:200:08:48:09
- 01: c844d54f5f1f6c0e3e4a2557f76526e434214bf9f9659f2294d32f798d78e003 00865309 0 0/5 2017-09-05 12:14:23 08:343:16:56:14
- 02: 587d1c3eb2b2c0659278186ed8cca51c93571ccdac8db6c0eae2ed509f59090a 00887929 4 6/84 2017-11-06 23:42:15 08:281:05:28:22
- 03: 4b1344919a449aee8a3108957458869897cac424f654cb09e94888fe5b183038 00965485 4 15/61 2018-06-08 19:14:24 08:067:09:56:13
key image 01: e2ff4bc724e75353f4e3be7bc80e45e0d0aec800914302b7a3cbb097ed8fe375 amount: 0.080000000000
ring members blk ring size in/out timestamp age [y:d:h:m:s]
- 00: 5a18f6579ad9f36173e919bdd82931598131a9a6bd3ce7d559832077e1b27cda 00037506 0 0/8 2014-07-04 01:06:54 12:043:04:03:43
- 01: 0445c0e24a4eacfe4aa422dbe25e9b8951e3682bc2425284d17ebd1a4f39b542 00888199 3 3/10 2017-11-07 21:45:30 08:280:07:25:07
- 02: e50bdca9c1b3e951429e697831067da732e3aee6927a0efed2d2a3a9a5b8aeba 00964663 4 18/51 2018-06-06 13:01:27 08:069:16:09:10
- 03: 5c38024221c6de6668b55231379f950127c86a8ca381c8d050ea1c80a2ade9f8 00965295 4 3/57 2018-06-08 06:47:02 08:067:22:23:35
key image 02: 9d27ba92059f9477fa0f59368d34c0c15534ebace7de77c26069de839a886b1a amount: 9.000000000000
ring members blk ring size in/out timestamp age [y:d:h:m:s]
- 00: 6d8afaec9bb01710f9f41bfa9de9855682ce0b0297741b4c3d49f55ff1064299 00955995 0 0/4 2018-05-13 22:18:10 08:093:06:52:27
- 01: af4bf171b4c71e6fcb13bda0e1342af33bb1e71cc2e86b742d2bf66d18ed972c 00962002 0 0/4 2018-05-30 10:44:18 08:076:18:26:19
- 02: b3c1d56c3dd4cf96fb6bf91d94e9a7f41cfb9f398b5ba363af37abd51dcc28ce 00965505 0 0/4 2018-06-08 20:14:56 08:067:08:55:41
- 03: 1a522611b0e262684a77e70c7fa22d1ea5791dedd74e03911d0d945b04271829 00965509 0 0/4 2018-06-08 20:32:55 08:067:08:37:42
key image 03: 786215a0cadbcd99babbb5af3fa8811dafc5ddfb330d7f7a2bfdecb04709acd8 amount: 0.010000000000
ring members blk ring size in/out timestamp age [y:d:h:m:s]
- 00: 3e71464cae7f450b47839398860af8f9539b45849f455e323d74fa0351bbc581 00811529 4 19/52 2017-04-09 11:43:33 09:127:17:27:04
- 01: 72063711e6fd7e355bc82d67a8aa9ecf31a3f474ce72698ab21279091a661fad 00932155 3 14/147 2018-03-09 08:59:26 08:158:20:11:11
- 02: a78a622091ab33436dd22ac4259a45d672a190f2d0f7b655e0a9a2ce8e98e081 00938644 3 11/114 2018-03-27 10:11:59 08:140:18:58:38
- 03: f4794a26ddd3c5c09d5df3a564ab5dd8bd244a397a95fe630af8505ecce08f43 00965576 4 11/49 2018-06-09 01:15:31 08:067:03:55:06
key image 04: 2e55f1c298d59f1eeae9f3a2a4f2692009cb26c0956bdf8ea3081add1da9d438 amount: 0.010000000000
ring members blk ring size in/out timestamp age [y:d:h:m:s]
- 00: 5ed49cb6934daf09a88c742f107daee3d92edfa05dd67e7e237920b0af4e85c7 00862159 0 0/5 2017-08-28 05:07:52 08:352:00:02:45
- 01: 864a27054425a702f56754faa8fdcc44ee33df4700f6b104630842c5a0788b5b 00965255 4 2/12 2018-06-08 04:42:03 08:068:00:28:34
- 02: 7bc08baf5a391e0ee17df6249b3c0d4132359d14e44b03016c13ff0a431e197d 00965407 4 2/55 2018-06-08 13:40:06 08:067:15:30:31
- 03: 6cd62a8605b692fa65261c39e3cc458ade5184f7c8dd002949d65217f8549a4f 00965468 4 1/50 2018-06-08 17:36:08 08:067:11:34:29
{ "version": 1, "unlock_time": 0, "vin": [ { "key": { "amount": 10000000000, "key_offsets": [ 116663, 112271, 22905, 81219 ], "k_image": "f19966b25cada4c099197ce02a9f523ddc2946d2508e0b4281b8730f08631ba6" } }, { "key": { "amount": 80000000000, "key_offsets": [ 54653, 163191, 54567, 371 ], "k_image": "e2ff4bc724e75353f4e3be7bc80e45e0d0aec800914302b7a3cbb097ed8fe375" } }, { "key": { "amount": 9000000000000, "key_offsets": [ 103528, 5997, 3742, 4 ], "k_image": "9d27ba92059f9477fa0f59368d34c0c15534ebace7de77c26069de839a886b1a" } }, { "key": { "amount": 10000000000, "key_offsets": [ 188937, 114194, 6590, 23396 ], "k_image": "786215a0cadbcd99babbb5af3fa8811dafc5ddfb330d7f7a2bfdecb04709acd8" } }, { "key": { "amount": 10000000000, "key_offsets": [ 226542, 106358, 108, 39 ], "k_image": "2e55f1c298d59f1eeae9f3a2a4f2692009cb26c0956bdf8ea3081add1da9d438" } } ], "vout": [ { "amount": 500000000000, "target": { "key": "aa702f7c10e90bcac85abbfc5b3af8576b89acae8ddec2d69693aca772d389e4" } }, { "amount": 8000000000, "target": { "key": "09e9725be9f606d6641162e1f0ef40e0edcef8106cafc5f01aabdec5639683dc" } }, { "amount": 500000000000, "target": { "key": "f13ef8e1fb8d80e57f99b272ef6b51d3aaae3e27b94cc6455bd5517c5e9bf4cf" } }, { "amount": 7000000000, "target": { "key": "15a1d51dccdea5fd2946e7305abced7063b643d92e6bd9258a5fed4aa8bd10bd" } }, { "amount": 5000000000, "target": { "key": "595c901272839bfdb87cf47ae9cbd43bea250ed278ca56472429beff6eedb107" } }, { "amount": 500000000000, "target": { "key": "6d7dca2a4efe31ebe8774a05cc4cb9cb06fb60ad0c0ae1b6dc867c9c0365ba4f" } }, { "amount": 6000000000, "target": { "key": "8b05e13c557ad45fb637ecef1403f501e79f85303047d5755b01d0a7ecce58f7" } }, { "amount": 1000000000000, "target": { "key": "4d70f2d46babdc141934468731c4df28281999774c63d6c58b5c2a435bd38b2b" } }, { "amount": 4000000000, "target": { "key": "7468ec03feeb70b87a7dca67bd07e443eafa247573719c895a9854caa4de8b1f" } }, { "amount": 5000000000, "target": { "key": "2473cfab5ea06c8f27f7aca94ccd3549b147b8e846d85ab75f403cd2311a1ffa" } }, { "amount": 30000000000, "target": { "key": "76e3121fc6d0cfb82f61ce228c810ff3fcb35b6d77149d2e9234850b03109471" } }, { "amount": 200000000000, "target": { "key": "51d163959030ae70236e1d3a580ea6525dfb017d22da172456434dbb2f3dff3c" } }, { "amount": 500000000000, "target": { "key": "dd00348e32933b8e3e886fb9f6597f2aa87416a457ca2b57136964b1eafc6792" } }, { "amount": 6000000000, "target": { "key": "c317ff95bec6478791459f0d6951cac45ce47318e751d38040dcc1b2d6ad59a2" } }, { "amount": 20000000000, "target": { "key": "ac6239ce516046770e129ea44b345178720985322eca48a0de91d7cbb86d119c" } }, { "amount": 9000000000, "target": { "key": "cd1d5fcf23f1da1608b2045d18122cad5a0887b448a3a527f6c2fc9f715adb8d" } }, { "amount": 10000000000, "target": { "key": "7c1509c886e92c7bd57075a313923a2c7caca71b2b359df3ba27ffe4c31d6dbc" } }, { "amount": 60000000000, "target": { "key": "fbaac575fff948faf49db22c7ecdad61e08eb2a081ccbacc9dc3cfe4d828cb30" } }, { "amount": 600000000000, "target": { "key": "03fd8ecd6cec4a9d1b8745bdd3cb4dead8f5c212254e5f5f09f604fe378d0028" } }, { "amount": 20000000000, "target": { "key": "82d2c03f153ebf9be5c0dc72dfe9a94a3440a2b15416c3c7af9670f4290e7d2b" } }, { "amount": 500000000000, "target": { "key": "68f822e501b61af08cb81d90f603d18b3e8a13f7e126adbada4baf94ff99006d" } }, { "amount": 10000000000, "target": { "key": "70b818fc2468c7dfdabe98d7f52accbe0e433305938c40a7341f37df79630158" } }, { "amount": 40000000000, "target": { "key": "267ab2d21688d49c803cc86f86b1d51698f112946df046821ce4fd4f72c150ab" } }, { "amount": 30000000000, "target": { "key": "e7d16fd0a6e147ab674b714cebf55d61a86614e7fc5c65e3e9d94ccb0842453f" } }, { "amount": 500000000000, "target": { "key": "9cc7dd0282231f8943d2022765feb8473afe0cfa79e291f30dbd952be69500c0" } }, { "amount": 500000000000, "target": { "key": "b2a69e6a55277a742545d9c4e818d9a734feb995866034ec09bf4afd49b98026" } }, { "amount": 500000000000, "target": { "key": "24486a3135402e5de795f2470c4e20c93623da83c9ab32bc02f105aae17db8a2" } }, { "amount": 30000000000, "target": { "key": "2427fafb95bd78cd0ab839f9b32a96d25c9564ab0b5bdeef8b38f1d37175f85f" } }, { "amount": 2000000000, "target": { "key": "f6d0dc03dd0feeb9e4c04669af72451349aa263de9364c5710e5f2e2994f6d41" } }, { "amount": 500000000000, "target": { "key": "7073ef882be95d986e2cde0e6e2bb5c1c23d95d53089966213871ab428751ce5" } }, { "amount": 90000000000, "target": { "key": "8cab5798fdb6236ff4efd477d3150e2f56f060140a5128135600b0c617a47e92" } }, { "amount": 500000000000, "target": { "key": "b70e636c023b44a0a21dfb45caa583610eebf1d96f3ef0d53c0b6ee8ea353c2c" } }, { "amount": 7000000000, "target": { "key": "bf705738925c35617a885892c93815fa4dd6399463b15420f5973f02c6dc99e9" } }, { "amount": 500000000000, "target": { "key": "f8ebc611e3fd1cd6550a5e836942683259f4d262dcf940306f794cdc79402944" } }, { "amount": 1000000000, "target": { "key": "c493b9078dc76ee1120b0c625551f72c8cd3b814365e9beec2beb9ce741fbacf" } }, { "amount": 4000000000, "target": { "key": "153663115b597a01f74d2dc86b552fab948892e1e05e2f37b4b52f68b1cd3ea1" } }, { "amount": 80000000000, "target": { "key": "454d36fc17c3886350ee27d3181ded5d0d48cc6ab17e6f766dbd66bc75a55c0a" } }, { "amount": 500000000000, "target": { "key": "64371dba351f1b0ddb2c3d7c737130cdb6ab9c180f64f92f3acc9f5febb08c87" } }, { "amount": 800000000000, "target": { "key": "44cadda5a3f4c50a84705e792aac489ab58a2fc8fcfe8c47396c6fa9f0a2c059" } }, { "amount": 9000000000, "target": { "key": "7156df0bb9e5357850bf7fc6fe7ea0eb4b5cfbacd951ef6a57c51c30421e7991" } } ], "extra": [ 1, 43, 67, 91, 43, 96, 36, 109, 98, 210, 26, 82, 60, 160, 149, 38, 12, 238, 74, 53, 238, 221, 65, 217, 90, 97, 207, 197, 45, 226, 194, 65, 124 ], "signatures": [ "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", "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", "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", "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", "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"] }


Less details
source code | explorer version (api): aeon-2020-08-31-77e814c (1.1) | Aeon version: 0.14.1.0-02c9846a