The block example (it is
№107764):
{
"hash":"00000000000271de9d8b94afff543366e290e995f3e3e337bb86a0b7bf02e8d1",
"ver":1,
"prev_block":"00000000000148c04e58dca8e1a2df251339c81e2dfe1ff0e9d655b7b4ca428d",
"mrkl_root":"72febc107470c4f83e224f9683a5c7fb24c4dece8412b9d95db277c8dd75451d",
"time":1297566305,
"bits":453150034,
"nonce":329961997,
"n_tx":2,
"size":473,
"tx":[
{
"hash":"d74f0f8e979dc08d028f0fd97e06b97b81b3f42f41c80ce5e4a900003c202abe",
"ver":1,
"vin_sz":1,
"vout_sz":1,
"lock_time":0,
"size":134,
"in":[
{
"prev_out":{
"hash":"0000000000000000000000000000000000000000000000000000000000000000",
"n":4294967295
},
"coinbase":"045285021b0135"
}
],
"out":[
{
"value":"50.00000000",
"scriptPubKey":"045ac21e53fc77ea47b72ae306840bd7eb16709b04488a0daf177df6a2476bbd6fabf76731e1cbfa75ec55c575454fe89e41ce58993f1cbd3dcf497b85bbebab80 OP_CHECKSIG"
}
]
},
{
"hash":"8ddf80cb3f3286922752da908f3b3f96c4bd8114cd67f3e00ae6a130e7d37b6e",
"ver":1,
"vin_sz":1,
"vout_sz":2,
"lock_time":0,
"size":258,
"in":[
{
"prev_out":{
"hash":"4f41d46faa2e34b718e7edf051e27fbfe2e77055e5a4519eda67068cc060141b",
"n":0
},
"scriptSig":"3045022013402505fee0e884206e6ae22b8057227ce2de970fae57ad4ab95c616fc60418022100aa52d63f3cd6c9e17c2ba4a7410d68e8f4c25e77f7f08f161c2f1af116cc065401 045216f2b5745cf08681a1409aa83e1554c788a7365600c7378665895a5377960eb49a86e3a2128d2ffe5f52e6a6e5ed453a1b87ebf08e5fdbe0b98352be2719cf"
}
],
"out":[
{
"value":"0.05000000",
"scriptPubKey":"OP_DUP OP_HASH160 8707482c01949460fad582ef14558cbf1a2baf28 OP_EQUALVERIFY OP_CHECKSIG"
},
{
"value":"47.98000000",
"scriptPubKey":"OP_DUP OP_HASH160 5b83f29112290e0baf004db04a85c1e32a7f4242 OP_EQUALVERIFY OP_CHECKSIG"
}
]
}
],
"mrkl_tree":[
"d74f0f8e979dc08d028f0fd97e06b97b81b3f42f41c80ce5e4a900003c202abe",
"8ddf80cb3f3286922752da908f3b3f96c4bd8114cd67f3e00ae6a130e7d37b6e",
"72febc107470c4f83e224f9683a5c7fb24c4dece8412b9d95db277c8dd75451d"
]
}
The hash of that block header:
00000000000271de9d8b94afff543366e290e995f3e3e337bb86a0b7bf02e8d1
The current target:
0000000000028552000000000000000000000000000000000000000000000000
The cryptoproblem is that the block header SHA-256 hash should be below the current target.